US President Donald Trump's speech at the UN General Assembly got off to an unusual start when world leaders and diplomats laughed at his claim that his administration has accomplished more than any other in US history.

Responding to the laughs, Trump said, "Didn't expect that reaction, but that's OK."

Trump later claimed he meant to make the audience laugh.

Trump has had a troubled relationship with the UN since entering the White House.

At time he's characterized the institution as ineffectual and even unnecessary.

World leaders and diplomats laughed at President Donald Trump's speech at the United Nations General Assembly in New York on Tuesday after he claimed his administration has accomplished more than any other in US history.

"In less than two years, my administration has accomplished more than almost any administration in the history of our country," Trump said, prompting the laughter.

Responding to the laughs, Trump said, "Didn't expect that reaction, but that's OK."

Trump often criticized former US President Barack Obama's approach to foreign affairs and claimed the world was "laughing" at the country under Obama's leadership.

In 2014 Trump tweeted: "We need a President who isn't a laughing stock to the entire World. We need a truly great leader, a genius at strategy and winning. Respect!"

But Trump's bombastic foreign policy has faced significant criticism at home and abroad, and polls have shown a that majority of Americans surveyed feel the US has lost respect worldwide under his leadership. Trump's unilateral approach to foreign affairs has marked a stark contrast from his predecessor.

Correspondingly, Trump has had a troubled relationship with the UN, an institution he's characterized as ineffectual and even unnecessary. He's drawn ire from the UN over his attacks on the press and decisions such as withdrawing from the landmark Paris climate accord, among other issues.

Trump used his speech on Tuesday to tout his administration's accomplishments, decry US adversaries like Iran, and touch on issues over which he's long expressed concern, such as global trade and mass migration.

Hours after his speech, Trump claimed he meant to make the audience laugh during his speech, despite initially stating he didn't "expect that reaction."

"Oh it was great. Well, that was meant to get some laughter, but it was great," Trump told reporters when questioned about the laughter on Tuesday afternoon.