Meanwhile, 2½ years into Ukraine's war with Russia, some congressional now openly oppose continuing to provide U.S. arms to Ukraine as it holds on through battle after battle, with a murky path forward.
"We could have stood by and merely protested, but Vice President and I understood that that was an assault on everything this institution was supposed to stand for," Biden said. "And so, with my direction America stepped into the breach, providing massive security and economic and humanitarian assistance."
Biden celebrated the expansion of the NATO in the wake of Russian President 's invasion of Ukraine. But he told the room of foreign leaders that they "cannot let up."
"You cannot grow weary," he said. "You cannot look away. We will not let up on our support for Ukraine, not until Ukraine wins a just and durable peace."
Biden also addressed his decision to of the in July, calling on other leaders to put their countries' people over their own political ambitions.
"As much as I love the job, I love my country more. I decided, after 50 years of public service, it's time for a new generation of leadership to take my nation forward," he said. "My fellow leaders, let us never forget: Some things are more important than staying in power."
Biden has a packed schedule of high-level meetings to work through the onslaught of geopolitical problems in closed-door settings.
On Sept. 21, Biden hosted a summit in his hometown of Wilmington, Delaware, with the leaders of Australia, India and Japan.
On Monday, Biden met with United Arab Emirates President Mohamed bin Zayed Al Nahyan in Washington. Following his speech on Tuesday in New York, Biden will host a summit on the ongoing effort to fight the trafficking of synthetic drugs.
On Wednesday, he will meet with President Tô Lâm of Vietnam, the White House said. On Thursday, Biden will host Ukraine's president, Volodymyr Zelenskyy in Washington.
As Biden wraps up his presidency, foreign leaders are also making time in their U.S. itineraries to meet with his potential successors: Harris and former President , the two major party nominees in November's election.
Harris had her own sit-down with the UAE president on Monday, and she will meet with Zelenskyy on Thursday in Washington.
Trump is also expected to meet with Zelenskyy, along with Indian Prime Minister Narendra Modi and President Andrzej Duda of Poland, sources from his campaign told NBC News.
