President Joe Biden declared in his final address to the U.N. General Assembly on Tuesday that the U.S. must not retreat from the world, as Israel and Hezbollah militants in Lebanon edged toward all-out war and Israel’s bloody operation against Hamas in Gaza neared the one-year mark.

Biden used his wide-ranging address to speak to a need to end the Middle East conflict and the 17-month-old civil war in Sudan and to highlight U.S. and Western allies’ support for Kyiv since Russia invaded Ukraine in February 2022. He also raised concern over artificial intelligence and its potential to be used for repression.

His appearance before the international body offered Biden one of his last high-profile opportunities as president to make the case to keep up robust support for Ukraine, which could be in doubt if former President Donald Trump defeats Vice President Kamala Harrisin November. Biden insisted that despite global conflicts, he remains hopeful for the future.

“I’ve seen a remarkable sweep of history,” Biden said. “I know many look at the world today and see difficulties and react with despair but I do not.”

“We are stronger than we think” when the world acts together, he added.

Biden came to office promising to rejuvenate U.S. relations around the world and to extract the U.S. from “forever wars” in Afghanistan and Iraq that consumed American foreign policy over the last 20 years.

“I was determined to end it, and I did,” Biden said of the Afghanistan exit, calling it a “hard decision but the right decision.” He acknowledged that it was “accompanied by tragedy” with the deaths of 13 American troops and hundreds of Afghans in a suicide bombing during the chaotic withdrawal.

But his foreign policy legacy may ultimately be shaped by his administration’s response to two of the biggest conflicts in Europe and the Middle East since World War II.

“There will always be forces that pull our countries apart,” Biden said, rejecting “a desire to retreat from the world and go it alone.” He said, “Our task, our test, is to make sure that the forces holding us together are stronger than the forces pulling us apart.”