By AAMER MADHANI and ZEKE MILLER | Associated Press

UNITED NATIONS (AP) — President Joe Biden declared at the United Nations on Wednesday that Russia has “shamelessly violated the core tenets” of the international body with its war in Ukraine as he summoned nations around the globe to stand firm in backing the Ukrainian resistance.

Delivering a forceful condemnation of Russia’s seven-month invasion, Biden said reports of Russian abuses against civilians in Ukraine “should make your blood run cold.” And he said President Vladimir Putin’s new nuclear threats against Europe showed “reckless disregard” for Russia’s responsibilities as a signer of the Treaty on the Non-Proliferation of Nuclear Weapons.

He criticized Russia for scheduling “sham referenda” this week in territory it has forcibly seized in Ukraine.

“A permanent member of the U..N Security Council invaded its neighbor, attempted to erase a sovereign state from the map. Russia has shamelessly violated the core tenets of the U.N. charter,” he told his U.N. audience.

Biden called on all nations, whether democracies or autocracies, to speak out against Russia’s “brutal, needless war” and to bolster’s Ukraine effort to defend itself.

“We will stand in solidarity against Russia’s aggression, period,” Biden said.

Biden also highlighted consequences of the invasion for the world’s food supply, pledging $2.9 billion in global food security aid to address shortages caused by the war and the effects of climate change. He praised a U.N.-brokered effort to create a corridor for Ukrainian grain to be exported by sea, and called on the agreement to be continued despite the ongoing conflict.

Biden, during his time at the U.N. General Assembly, also planned to meet Wednesday with new British Prime Minister Liz Truss and press allies to meet an $18 billion target to replenish the Global Fund to Fight AIDS, tuberculosis and malaria.

But the heart of the president’s visit to the U.N. this year was his full-throated censure of Russia as its war nears the seven-month mark. One of Russia’s deputy U.N. ambassadors, Gennady Kuzmin, was sitting in Russia’s seat during Biden’s speech.

The address came as Russian-controlled regions of eastern and southern Ukraine have announced plans to hold Kremllin-backed referendums in days ahead on becoming part of Russia and as Moscow is losing ground in the invasion. Russian President Putin on Wednesday announced a partial mobilization to call up 300,000 reservists and accused the West of engaging in “nuclear blackmail.”

The White House said the global food security funding includes $2 billion in direct humanitarian assistance through the United States Agency for International Development. The balance of the money will go to global development projects meant to boost the efficiency and resilience of the global food supply.

“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.

Biden was confronting no shortage of difficult issues as leaders gather this year.

In addition to the Russian war in Ukraine, European fears that a recession could be just around the corner are heightened. Administration concerns grow by the day that time is running short to revive the Iran nuclear deal and over China’s saber-rattling on Taiwan.

When he addressed last year’s General Assembly, Biden focused on broad themes of global partnership, urging world leaders to act with haste against the coronavirus, climate change and human rights abuses. And he offered assurances that his presidency marked a return of American leadership to international institutions following Donald Trump’s “America First” foreign policy.

But one year later, global dynamics have dramatically changed.

His Wednesday address comes on the heels of Ukrainian forces retaking control of large stretches of territory near Kharkiv. But even as Ukrainian forces have racked up battlefield wins, much of Europe is feeling painful blowback from economic sanctions levied against Russia. A vast reduction in Russian oil and gas has led to a sharp jump in energy prices, skyrocketing inflation and growing risk of Europe slipping into a recession.

Biden’s visit to the U.N. also comes as his administration’s efforts to revive the 2015 Iran nuclear deal appears stalled.

The deal brokered by the Obama administration — and scrapped by Trump in 2018 — provided billions of dollars in sanctions relief in exchange for Iran’s agreement to dismantle much of its nuclear program and open its facilities to extensive international inspection.

“While the United States is prepared for a mutual return to the Joint Comprehensive Plan of Action, if Iran steps up to its obligations, the United States is clear: We will not allow Iran to acquire nuclear weapons,” Biden said.

U.S. National Security Adviser Jake Sullivan said no breakthrough with Iran was expected during the General Assembly and that administration officials would be consulting with fellow signers of the 2015 agreement on the sidelines of this week’s meetings.

This year’s U.N. gathering is back to being a full-scale, in-person event after two years of curtailed activity due to the pandemic. In 2020, the in-person gathering was canceled and leaders instead delivered prerecorded speeches; last year was a mix of in-person and prerecorded speeches. Biden and first lady Jill Biden were set to host a leaders’ reception on Wednesday evening.

China’s President Xi Jinping opted not to attend this year’s U.N. gathering, but his country’s conduct and intentions will loom large.

Weeks after tensions flared across the Taiwan Strait as China objected to the high-profile visit to Taiwan of House Speaker Nancy Pelosi, Biden called for “peace and stability” and said the U.S. would “oppose unilateral changes in the status quo by either side.” That came days after Biden repeated that the U.S. would militarily assist Taiwan if China sought to invade.

China’s government on Monday said Biden’s statement in a CBS “60 Minutes” interview that American forces would defend the self-ruled island was a violation of U.S. commitments on the matter, but it gave no indication of possible retaliation.

Biden on Wednesday also declared that “fundamental freedoms are at risk in every part of our world,” citing last month’s U.N. human rights office report raising concerns about possible “crimes against humanity” in China’s western region against Uyghurs and other largely Muslim ethnic groups.

He also singled out for criticism the military junta in Myanmar, the Taliban controlling Afghanistan, and Iran, where he said the U.S. supports protests in Iran that sprang up in recent days after a 22-year-old woman died while being held by the morality police for violating the country’s Islamic dress code.

“Today we stand with the brave citizens and the brave women of Iran, who right now are demonstrating to secure their basic rights,” Biden said. “The United States will always promote human rights and the values enshrined in the U.N. Charter in our own country and around the world.”

AP writer Zeke Miller reported from Washington.