23日（米国時間）、バイデン大統領は、ロシアによるウクライナへの侵攻が「unprovoked and unjustified attack」であり、「この攻撃によって生じる死と破壊の責任はロシアのみにある」と非難した。
Statement by President Biden on Russia’s Unprovoked and Unjustified Attack on Ukraine
The prayers of the entire world are with the people of Ukraine tonight as they suffer an unprovoked and unjustified attack by Russian military forces. President Putin has chosen a premeditated war that will bring a catastrophic loss of life and human suffering. Russia alone is responsible for the death and destruction this attack will bring, and the United States and its Allies and partners will respond in a united and decisive way. The world will hold Russia accountable.
I will be monitoring the situation from the White House this evening and will continue to get regular updates from my national security team. Tomorrow, I will meet with my G7 counterparts in the morning and then speak to the American people to announce the further consequences the United States and our Allies and partners will impose on Russia for this needless act of aggression against Ukraine and global peace and security. We will also coordinate with our NATO Allies to ensure a strong, united response that deters any aggression against the Alliance. Tonight, Jill and I are praying for the brave and proud people of Ukraine.
attackは、国連憲章第51条における自衛権の行使の要件であるarmed attack（武力攻撃）を想起させる表現で、訳は「攻撃」となる。国際法上の武力不行使原則は、use of forceを禁止しているが、武力攻撃は、より限定的な対象となるため、深刻な国際法の違反であることを含意している。
unjustifiedは、「正当化できない」あるいは「不当な」と訳せる。武力行使を正当化する、安全保障理事会決議、自衛権、その他の慣習国際法上のルールにのっとっていないことを含意している。
unprovokedは、メディアで「いわれのない」や「理不尽」などと訳され、定まっていない。重要なのは、ロシアがNATOの拡大によって今回の侵攻が不可避となったとロジックを組み立てているため、それに対する返答であることで、ロシアが対抗しようとする挑発（provoke）がそもそもないことを含意している。
24日、NATO事務局長は次のようにロシアの「侵略」を非難した。
I strongly condemn Russia’s reckless and unprovoked attack on Ukraine, which puts at risk countless civilian lives. Once again, despite our repeated warnings and tireless efforts to engage in diplomacy, Russia has chosen the path of aggression against a sovereign and independent country. This is a grave breach of international law, and a serious threat to Euro-Atlantic security. I call on Russia to cease its military action immediately and respect Ukraine’s sovereignty and territorial integrity. NATO Allies will meet to address the consequences of Russia’s aggressive actions. We stand with the people of Ukraine at this terrible time. NATO will do all it takes to protect and defend all Allies.
ラトビア首相は、北大西洋条約4条に基づく協議を要請すると述べた。
https://twitter.com/krisjaniskarins/status/1496708315077881866?s=20&t=4Xcr8XFBZ4yqMpi1Ah9s4A
24日15時、ゼレンスキー大統領はバイデン大統領・ショルツ首相・ミシェルEU理事会議長・ジョンソン首相等と会談した後、「防衛・財政面での支援」を要請する旨のツイートを行なった。その後、ウクライナがロシアとの外交関係を断絶した旨報じられた。
https://twitter.com/ZelenskyyUa/status/1496728317969539076?s=20&t=7chaT8FnfxUV58Yud_7h_w
これに対し、NATO事務局長はウクライナへの派兵の予定はないと発表。
25日、NATO加盟国の元首・政府の長が声明を発表した。
Russia bears full responsibility for this conflict. It has rejected the path of diplomacy and dialogue repeatedly offered to it by NATO and Allies. It has fundamentally violated international law, including the UN Charter. Russia’s actions are also a flagrant rejection of the principles enshrined in the NATO-Russia Founding Act: it is Russia that has walked away from its commitments under the Act. [...] Our commitment to Article 5 of the Washington Treaty is iron-clad. We stand united to protect and defend all Allies. Freedom will always win over oppression.
26日の記者会見で、NATO事務局長はサイバー攻撃もNATO条約5条の発動条件となり得ると述べた。事務局長はこの解釈を2019年に既に示していた。
Three Things to Know About NATO's Role in Responding to the Ukraine Crisis
→NATOの果たしうる3つの役割について
EU加盟国は24日に共同声明を発表した。
We condemn in the strongest possible terms Russia's unprecedented military aggression against Ukraine. By its unprovoked and unjustified military actions, Russia is grossly violating international law and undermining European and global security and stability. We also condemn the involvement of Belarus in this aggression against Ukraine and call on it to abide by its international obligations. We demand that Russia immediately ceases military actions, unconditionally withdraws all forces and military equipment from the entire territory of Ukraine and fully respects Ukraine's territorial integrity, sovereignty and independence. Such use of force and coercion has no place in the 21st century. We will meet later today to discuss this blatant aggression and agree in principle on further restrictive measures that will impose massive and severe consequences on Russia for its action, in close coordination with our transatlantic partners. We deplore the loss of life and humanitarian suffering. The EU and its Member States are ready to urgently provide humanitarian emergency response. We call on Russia and Russia-backed armed formations to respect international humanitarian law. The EU stands firmly by Ukraine and its people as they face this war. The EU will provide further political, financial and humanitarian assistance. We are coordinating our response with our neighbours and international partners, including NATO and G7 whose leaders will be meeting shortly.
EU：ウクライナ問題特設ページ
3月1日、ゼレンスキー大統領がEU加盟申請書に署名した。
https://twitter.com/UA_EUMission/status/1498342584468525059?s=20&t=NArCF24yTUUkjOVJ4hyHBA
EU条約42条7項は、構成国への武力攻撃の際の、他の構成国の国連憲章51条に従った援助義務を定めている。
If a Member State is the victim of armed aggression on its territory, the other Member States shall have towards it an obligation of aid and assistance by all the means in their power, in accordance with Article 51 of the United Nations Charter. This shall not prejudice the specific character of the security and defence policy of certain Member States.
もっとも、集団的自衛権の行使まで義務づけているかは特に第2文（”Irish clause”）のために曖昧で、2015年のパリ同時多発テロの際にフランスが初めてこの規定を援用した際の各国の対応も様々だった。
Ambiguous alliance: Neutrality, opt-outs, and European defence
The President signed a decree on the declaration of a state of emergency
東京新聞によれば、岸田首相は24日の参議院予算委員会にて次のように「侵攻」を非難した。
今回のロシアによる侵攻は、力による一方的な現状変更を認めないとする国際秩序の根幹を揺るがすものであり、ロシアを強く非難するとともに、米国をはじめとする国際社会と連携して迅速に対処していく
26日午前、林外相はウクライナ・米国の外相とそれぞれ順次電話会談を行い、ロシアの行為を「侵略」と表現した。その後の記者会見でも同様の表現を用いた。
林大臣から、今回のロシアによる侵略を始めとする一連の行動は、ウクライナの主権及び領土一体性を侵害し、武力の行使を禁ずる国際法の重大な違反であり、決して認められないこと、力による一方的現状変更は、国際秩序の根幹を揺るがすものであり、ロシアを強く非難する旨述べました。（日ウクライナ外相会談）
両外相は、今回のロシア軍による侵略は、ウクライナの主権及び領土一体性を侵害し、武力の行使を禁ずる国際法に深刻に違反するとともに、力による一方的な現状変更を認めないとの国際秩序の根幹を揺るがすものであり、この影響は欧州にとどまるものではないとの認識を共有し、ロシアを厳しく非難しました。（日米外相会談）
Bloomberg: Can you say then China considers Russia’s action an invasion? Is it an invasion? Is it a violation of the UN Charter?
Hua Chunying: We have stated China’s principled position on the Ukraine issue. There is a complex historical background and context on this issue. The current situation is the result of the interplay of various factors.
We noted that today Russia announced its launch of a special military operation in eastern Ukraine. Russia’s defense ministry said that its armed forces will not conduct missile, air or artillery strikes on cities. China is closely monitoring the latest developments and calls on all sides to exercise restraint and prevent the situation from getting out of control.
I would like to stress once again China’s consistent position. We should pursue common, cooperative and sustainable security for all countries. The legitimate security concerns of all sides should be respected and resolved. We hope all sides will keep the door to peace open and continue to work for deescalation through dialogue, consultation and negotiation and prevent further escalation.
24日、閣僚委員会がロシアを非難する決定を採択していたところ、25日にはロシアの代表権を停止した。ロシアは加盟国の地位を保持し、欧州人権裁判所での対ロシア事件は継続し、また同国籍の裁判官も職務を継続する。→別記事
2月24日、議長を務めるセネガル大統領のMacky Sallが声明を発表し、ロシアに国際法と領土保全の尊重を求めた。
The current Chair of the African Union and President of Senegal, president Macky Sall, and the Chairperson of the African Union Commission, Moussa Faki Mahamat, express their extreme concern at the very serious and dangerous situation created in Ukraine. They call on the Russian Federation and any other regional or international actor to imperatively respect international law, the territorial integrity and national sovereignty of Ukraine. The Chair of the African Union and the Chairperson of the African Union Commission urge the two Parties to establish an immediate ceasefire and to open political negotiations without delay , under the auspices of the United Nations, in order to preserve the world from the consequences of planetary conflict, and in the interests of peace and stability in international relations in service of all the peoples of the world.
2022年2月25日、ロシアを非難する宣言を採択。
OAS Member States Condemn Russian Attack on Ukraine
ANTIGUA AND BARBUDA, BARBADOS, BELIZE, CANADA, CHILE, COLOMBIA, COSTA RICA, THE DOMINICAN REPUBLIC, ECUADOR, GRENADA, GUATEMALA, GUYANA, HAITI, JAMAICA, MEXICO, PANAMA, PARAGUAY, PERU, SURINAME, TRINIDAD AND TOBAGO, THE BAHAMAS, THE UNITED STATES AND VENEZUELA TO THE ORGANIZATION OF AMERICAN STATES
この宣言に名前を連ねないOAS加盟国は、加盟国の一覧と照らし合わせると、次のとおり
Argeitna, Bolivia, Brazil, Cuba, Dominica (Commonwealth of), El Salvador, Honduras, Nicaragua, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines
27日、加盟国外相が声明を発表した。ロシアへの明示的非難は含まれていない。
https://twitter.com/peacepalacekh/status/1497759223245344775?s=21
2月25日、理事会第225回会期にてウクライナ情勢について話し合われ、理事国らが国連憲章とシカゴ条約1条の違反を非難した。
Council States condemned the violation of the territorial integrity and sovereignty of a United Nations Member State, including its airspace, as being inconsistent with the principles of the Charter of the United Nations and Article 1 of the Convention on International Civil Aviation (Chicago Convention).
3月1日、世界銀行とIMFは合同で声明を発表した。
WASHINGTON, Mar. 1, 2022 – International Monetary Fund (IMF) Managing Director Kristalina Georgieva and World Bank Group President David Malpass today issued the following statement on the war in Ukraine.
“We are deeply shocked and saddened by the devastating human and economic toll brought by the war in Ukraine. People are being killed, injured, and forced to flee, and massive damage is caused to the country’s physical infrastructure. We stand with the Ukrainian people through these horrifying developments. The war is also creating significant spillovers to other countries. Commodity prices are being driven higher and risk further fueling inflation, which hits the poor the hardest. Disruptions in financial markets will continue to worsen should the conflict persist. The sanctions announced over the last few days will also have a significant economic impact. We are assessing the situation and discussing appropriate policy responses with our international partners.
“Our institutions are working together to support Ukraine on the financing and policy fronts and are urgently increasing that support. We have been in daily contact with the authorities on crisis measures. At the IMF, we are responding to Ukraine’s request for emergency financing through the Rapid Financing Instrument, which our Board could consider as early as next week. In addition, we continue to work on Ukraine’s Stand-By Arrangement program, under which an additional $2.2 billion is available between now and the end of June. At the World Bank Group, we are preparing a $3 billion package of support in the coming months, starting with a fast-disbursing budget support operation for at least $350 million that will be submitted to the Board for approval this week, followed by $200 million in fast-disbursing support for health and education. This package will include the mobilization of financing from several development partners, and we welcome the already-announced support from many bilateral partners.
“The World Bank and the IMF are also working together to assess the economic and financial impact of the conflict and refugees on other countries in the region and the world. We stand ready to provide enhanced policy, technical, and financial support to neighboring countries as needed. Coordinated international action will be crucial to mitigate risks and navigate the treacherous period ahead. This crisis affects the lives and livelihoods of people around the world, and we offer them our full support.”
https://twitter.com/wto/status/1499078002721837056?t=w1leROjKcRMvQ6tzbpuecQ&s=19
3月3日、国連総会決議採択を受けて声明を発表し、特に文化財等への攻撃の即時中止等を求めた。→別記事
3月3日にロシアの国家報告審査の延期を発表する文書の中で、ロシアの国連憲章違反への懸念を表明した。→別記事
3月6日（日）、ウクライナ、戦争で「血と涙の川」 ローマ教皇が即時停戦呼び掛け（ロイター）
国際法の尊重を願うとともに、聖座（the Holy See - 主権を有する主体です）が平和に向けた役割を果たしていく用意があるとも述べておられます。