By ELLEN KNICKMEYER, Associated Press

WASHINGTON (AP) — Former Presidents Barack Obama and George W. Bush delivered rare open criticism of the Trump administration — and singer Bono held back tears as he recited a poem — in an emotional video farewell on Monday with staffers of the U.S. Agency for International Development.

Monday was the last day as an independent agency for the six-decade-old humanitarian and development organization, created by President John F. Kennedy as a peaceful way of promoting U.S. national security by boosting goodwill and prosperity abroad.

Secretary of State Marco Rubio has ordered USAID absorbed into the State Department on Tuesday.

The former presidents and Bono spoke during a videoconference with thousands in the USAID community, which was billed as a closed-press event to allow political leaders and others privacy for sometimes angry and often teary remarks. Parts of the video were shared with The Associated Press.

They expressed their appreciation for the thousands of USAID staffers who have lost their jobs and life’s work. Their agency was one of the first and most fiercely targeted for government-cutting by President Donald Trump and his billionaire ally Elon Musk, with staffers abruptly locked out of systems and offices and terminated by mass emailing.

Trump claimed the agency was run by “radical left lunatics” and rife with “tremendous fraud.” Musk called it “a criminal organization.”

Obama, speaking in a recorded statement, offered assurances to the aid and development workers, some listening from overseas.

“Your work has mattered and will matter for generations to come,” he told them.

Obama has largely kept a low public profile during Trump’s second term and refrained from criticizing the monumental changes that Trump has made to U.S. programs and priorities at home and abroad.

“Gutting USAID is a travesty, and it’s a tragedy. Because it’s some of the most important work happening anywhere in the world,” Obama said. He credited USAID with not only saving lives, but being a main factor in global economic growth that has turned some aid-receiving countries into U.S. markets and trade partners.

The former Democratic president called Trump’s dismantling of USAID a “colossal mistake” that hurts the U.S. and predicted that ”sooner or later, leaders on both sides of the aisle will realize how much you are needed.”

Asked for comment, the State Department said it would be introducing the department’s foreign assistance successor to USAID, to be called America First, this week.

“The new process will ensure there is proper oversight and that every tax dollar spent will help advance our national interests,” the department said.

USAID oversaw programs around the world, providing water and life-saving food to millions uprooted by conflict in Sudan, Syria, Gaza and elsewhere, sponsoring the “Green Revolution” that revolutionized modern agriculture and curbed starvation and famine, preventing disease outbreaks, promoting democracy, and providing financing and development that allowed countries and people to climb out of poverty.

Bush, who also spoke in a recorded message, went straight to the cuts in a landmark AIDS and HIV program started by his Republican administration and credited with saving 25 million lives around the world.

Bipartisan blowback from Congress to cutting the popular President’s Emergency Plan for AIDS Relief, known as PEPFAR, helped save significant funding for the program. But cuts and rule changes have reduced the number getting the life-saving care.

“You’ve showed the great strength of America through your work — and that is your good heart,’’ Bush told USAID staffers. “Is it in our national interests that 25 million people who would have died now live? I think it is, and so do you,” he said.

Former Liberian President Ellen Johnson-Sirleaf, former Colombian President Juan Manual Santos and former U.S. Ambassador to the U.N. Linda Thomas-Greenfield also spoke to the staffers.

So did humanitarian workers, including one who spoke of the welcome appearance of USAID staffers with food when she was a frightened 8-year-old child in a Liberian refugee camp. A World Food Program official vowed through sobs that the U.S. aid mission would be back someday.

Bono, a longtime humanitarian advocate in Africa and elsewhere, was announced as the “surprise guest,” in shades and a cap.

He jokingly hailed the USAID staffers as “secret agents of international development” in acknowledgment of the down-low nature of Monday’s unofficial gathering of the USAID community.

Bono held back tears at times as he recited a poem he had written to the agency and its gutting. He spoke of children dying of malnutrition, a reference to millions of people who Boston University researchers and other analysts say will die because of the U.S. cuts to funding for health and other programs abroad.

“They called you crooks. When you were the best of us,” Bono said.