Donald Trump reportedly stunned diplomats during his final summit with North Korean dictator Kim Jong Un in Hanoi, Vietnam, by offering the despot a lift home on Air Force One, according to the BBC documentary Trump Takes on the World. In the last of the three-part series, which aired Saturday, Matthew Pottinger, the top Asia expert on Trump’s National Security Council said the former U.S. president made the offer after the negotiations broke down after which Trump said, “Sometimes you just have to walk.” Pottinger said the offer was astonishing given that it would have put Kim inside the U.S. aircraft and placed that top-security jet in North Korean air space. “President Trump offered Kim a lift home on Air Force One,” Pottinger said. “The president knew that Kim had arrived on a multi-day train ride through China into Hanoi and the president said: ‘I can get you home in two hours if you want.’ Kim declined.”