US President Joe Biden accused Russia on Wednesday of violating the core tenets of membership in the United Nations by invading Ukraine and said Moscow was making "irresponsible" threats to use nuclear weapons.
Speaking at the United Nations General Assembly in New York, Biden slammed Russian President Vladimir Putin for starting an unprovoked war that some 40 U.N. members are helping Ukraine fight with funding and weapons.
"A permanent member of the United Nations Security Council invaded its neighbor, attempted to erase a sovereign state from the map. Russia has shamelessly violated the core tenets of the United Nations Charter," Biden said.
Earlier on Wednesday, Putin ordered a Russian mobilization to fight in Ukraine and made a thinly veiled threat to use nuclear weapons, in what NATO called a "reckless" act of desperation in the face of a looming Russian defeat.
"A nuclear war cannot be won and must never be fought," Biden said.
Biden said no one had threatened Russia, despite its claims to the contrary, and that only Russia had sought conflict. He pledged the United States would stand in solidarity with Ukraine.
The White House also announced $2.9 billion in additional US funding to combat global food insecurity, building on $6.9 billion in US food security funding already committed this year.
The United States has strengthened its focus on food security since Russia's Feb. 24 invasion of Ukraine worsened a global food crisis that was already fueled by climate change and the Covid-19 pandemic. Russia and Ukraine are major grain and fertilizer exporters and shipments were disrupted by the war.
The United Nations has said the conflict has pushed another 47 million people into "acute hunger."
The United States and Western allies are competing with Russia for diplomatic influence. The United States has acknowledged that some countries are concerned the Ukraine war had drawn global attention away from other crises.
"This new announcement of $2.9 billion will save lives through emergency interventions and invest in medium to long term food security assistance in order to protect the world's most vulnerable populations from the escalating global food security crisis," the White House said in a fact sheet.