Former U.S. President Donald Trump surprised diplomats during his final meeting with North Korea leader Kim Jong-un in Hanoi, Vietnam by offering the dictator a ride home on Air Force One, Business Insider reported Monday quoting a BBC documentary.

Talks had failed to make any headway over North Korea's nuclear program, leading Trump to suddenly withdraw from the summit in February 2019.

However, before he departed, Trump invited Kim to fly home to Pyongyang on the presidential plane, according to sources close to Trump.

Matthew Pottinger, a top Asia expert on Trump's National Security Council told BBC that then President Trump offered the North Korean strongman a ride home on Air Force One.

"The president knew that Kim had arrived on a multiday train ride through China to Hanoi and he said: 'I can get you home in two hours if you want.'

Kim rejected the offer, Pottinger said.

BBC's three-part series "Trump Takes On the World" reveals new details about how the former American commander in chief and Kim negotiated North Korea's nuclear activities.

"Trump obviously thought he had a new best friend in Kim," Trump's former national security adviser John Bolton said in remarks quoted by the Sunday Times.

"Trump thought that U.S.-North Korea relations were great because he and Kim were buddies. It's a very dangerous perception," Bolton, who has since fallen out with Trump, said.'

The remarkable relationship between Trump and his North Korean counterpart is represented by the American journalist Bob Woodward in his book "Rage," the Express reported.

Woodward gained access to 27 letters that Trump and Kim wrote to one another.

Trump described the missives as "love letters," Woodward wrote.

But, they're more than that. They reveal a decision by both men to become friends, he said.

Whether genuine or not, Woodward said that "probably only history will tell."