President Biden condemned Russia's invasion of Ukraine during his address to the United Nations General Assembly on Wednesday, saying it "is about extinguishing Ukraine's right to exist as a state — plain and simple."

Why it matters: Biden's remarks come after Putin doubled down on the invasion of Ukraine by ordering a "partial mobilization" of Russian reservists with military experience and issued a veiled threat about using nuclear weapons.

What they're saying: "Russia has shamefully violated the core tenets of the United Nations Charter," Biden said.

• "The world should see these outrageous acts for what they are. Putin claims he had to act because Russia was threatened. But no one threatened Russia, and no one other than Russia sought conflict."
• "This war is about extinguishing Ukraine's right to exist as a state — plain and simple. And Ukraine's right to exist as a people. Whoever you are, where ever you live, whatever you believe — that should make your blood run cold."
• "Ukraine has the same rights that belong to every sovereign nation. We will stand in solidarity with Ukraine. We will stand in solidarity against Russian aggression."

Biden announced the U.S. will allocate $2.9 billion to help address global food insecurity exacerbated by Russia's invasion and to help combat climate change.

• $2 billion in global aid will be distributed through USAID, and $783 million will go toward the development of agricultural and food production programs around the world, the White House said.
• He called on the UN Security Council to "refrain from the use of the veto except in rare, extraordinary circumstances" and said the U.S. supports the creation of additional permanent and non-permanent seats on the council for countries in Africa and Latin America.

Thought bubble, via Axios' Dave Lawler: Biden covered a very wide range of issues in a speech that ran for roughly double his allotted 15 minutes, but it was clear that he had one primary ambition: mobilizing countries against Russia’s invasion of Ukraine.

• Like President Emmanuel Macron of France on Tuesday, Biden argued that Putin’s invasion violated principles that all UN members hold dear, and thus no one — even countries that aren’t U.S. allies or fellow democracies — should be silent.
• He also appealed to the developing world by promising funding on food security, global health and climate finance, and arguing in favor of Palestinian statehood and adding seats to the UN Security Council.
• Interestingly, he referred directly to “our competition with China,” and said the U.S. would never ask countries to choose between the superpowers.

Russian President Vladimir Putin announced in a televised address Wednesday morning a partial mobilization of reservists to fight in Ukraine, the country's first mobilization since World War II.

• Putin made a veiled threat to use nuclear weapons, saying, "If the territorial integrity of our country is threatened, we will use all available means to protect our people — this is not a bluff."
• The mobilization suggests Russia is struggling with manpower shortages as casualties mount and morale for the invasion drops. It's also an abrupt reversal of the Kremlin's previous position that there would be no mobilization of any kind for the invasion.
• His address came after the Kremlin on Tuesday paved the way for referendums in four Ukrainian regions fully or partially occupied by the Russian military that could lead to the annexation of nearly 15% of Ukraine into the Russian Federation.
• Ukraine said the planned referendums would be illegal, while G7 countries and several other nations have said they will not recognize altered borders produced by the invasion.

The big picture: Putin announced the partial mobilization roughly two weeks after the Russian military suffered major territorial reversals in south and northeast Ukraine from twin counteroffensives.

• Through the counteroffensives, the Ukrainian military retook control of almost all of Kharkiv Oblast in the northeast and made made gains in Kherson Oblast in the southwest.

Go deeper ... UN chief: The "world is in big trouble"

Editor's note: This story has been updated with additional details.