WASHINGTON -- US Democratic presidential candidate Joe Biden lashed out at President Donald Trump on Thursday, arguing that he has made the United States less secure and more isolated in the world.

The former vice president also claimed the US president has made the United States a laughing stock on the global stage.

"We find ourselves in a position where we're more isolated in the world than we have ever been," Biden said, adding Trump's America First policy has left "America alone" in the world.

"We have ... our NATO allies publicly saying they can't count on us. We are in a situation as well where in the Far East, we find ourselves in, and in the western Pacific, where we're isolated as well," he said in a town hall meeting hosted by US television network ABC News.

Biden argued his country is less secure than it has ever been, partly because of North Korea possessing more nuclear weapons and long-range missiles.

"You have Iran closer to having enough nuclear material to build a bomb. North Korea has more bombs and missiles available to it," he said.

Biden's remarks came hours after Trump again took credit for preventing what he claims to have been an imminent nuclear war with North Korea.

"Remember, you would have been in a war without (me), because North Korea, we were going to have a nice nuclear war with North Korea," he said earlier in the day while campaigning in Greenville, North Carolina.

Trump frequently boasts of his personal and close relationship with North Korean leader Kim Jong-un, with whom he held the first and second-ever US-North Korea summits in June 2018 and February 2019.

Biden accused the US president of embracing "all the thugs in the world," including Russian President Vladimir Putin and China's Xi Jinping.

"I mean he is best friends with the leader of North Korea. He is sending love letters. He doesn't take on Putin in any way, and he is just, he has learned the art of the steal from the art of the deal by Xi in China," Biden said.

Biden also claimed the US has become a laughing stock because of Trump's lack of what he called a "coherent foreign policy."

"He has pulled out of almost every international organization. He gets laughed at, literally not figuratively, when he goes to the United Nations," he said.

"I mean it's just not about the president per se. It is about the nation, and their lack of respect is shown to us," he added.

In a recent interview with Yonhap News Agency, one of Biden's foreign policy advisers, Brian McKeon, said the Democratic candidate, if elected, would immediately reaffirm the US' commitment to its alliances to its key allies, including South Korea.

"(Biden) frequently says (that) when he takes office, he will immediately get on the phone with some of our key allies in Europe and Asia, and centrally say, 'America is back, and we have your back,'" McKeon has said. 

Trump and Biden were originally scheduled to hold their second presidential TV debate on the day, but the debate was canceled as Trump refused to do it virtually, a precautionary measure taken by the organizing committee for COVID-19.

The US president was admitted to a hospital after testing positive for the new coronavirus about two weeks ago. He has since recovered and tested negative in a recent series of tests, according to the White House.

The second and last presidential TV debate before the Nov. 3 presidential election is slated for next Thursday. (Yonhap)