WASHINGTON - North Korea allowed an American student who fell into a coma while imprisoned in a labour camp to be flown home on Tuesday as Washington stepped up efforts to halt Pyongyang's nuclear programme.
The release of Otto Warmbier, 18 months into a 15-year sentence, came as US President Donald Trump invited South Korea's new leader Moon
Secretary of State Rex Tillerson said his agency had "secured" the 22-year-old's release in talks with North Korea and is pushing for three more Americans to be freed.
It was not immediately clear if he had made any concessions.
The news came as flamboyant retired NBA basketball star Dennis Rodman - a former contestant on Trump's "Celebrity Apprentice" reality show - flew to Pyongyang to resume his quixotic quest to broker detente between his US homeland and Kim Jong-Un's authoritarian regime.
But State Department spokeswoman Heather Nauert said the visit "had nothing to do with the release."
"Otto has left North Korea," his parents Fred and Cindy Warmbier said in a statement to CNN.
Warmbier's parents were told their son was given a sleeping pill soon after his trial in March last year and never woke.
US officials refused to comment on Warmbier's condition, but former ambassador and New Mexico governor Bill Richardson said he had spoken
"Otto has been in a coma for over a year now and urgently needs proper medical care in the United States," said Richardson, who has previously served as a special envoy to North Korea and still works on prisoner issues.
"We received a call from Cindy and Fred Warmbier early today to update us on Otto's condition. In no uncertain terms, North Korea must explain the causes of his coma." Tillerson told US senators at the start of a budget hearing that the State Department had no comment on Mr Warmbier's condition, "out of respect for him and his family."
The United States had accused the North of using Warmbier as a political pawn and condemned the sentence as far out of proportion to his alleged crime.
The announcment came amid tension between Washington and Pyongyang following a series of missle tests by the North, focusing attention on an arms buildup that Pentagon chief Jim Mattis on Monday dubbed "a clear and present danger to all".
Almost immediately on taking office in January, Trump and his team - having been briefed by outgoing leader Barack Obama - declared the North's attempts to build, test and arm a nuclear-capable ballistic missle to be Washington's biggest
Washington has stepped up pressure on China and other foreign powers to enforce existing UN sanctions, and has deployed increased military assets of its own in the region.
The star has visited the Stalinist state at least four times before, most recently in 2014, when he attracted a deluge of criticism after being filmed singing happy birthday to his "friend for life," leader Kim.
Before arriving this time, Rodman told reporters that Trump would be happy with the trip, since he was "trying to accomplish something that we both need," sparking speculation that he may be operating as an unofficial envoy.
US officials dismissed this, saying he was travelling as a private citizen, but the basketball icon is probably Kim and Trump's only mutual friend.
"I have not spoken to Mr Rodman. I don't know why he is there," Nauert said.
"We strongly, strongly suggest that Americans do not go to North Korea. I'm not aware of any message that was sent."
Warmbier, a student at the University of Virginia, was arrested for removing a political banner from a wall at a North Korean hotel.
He was detained at the airport as he was leaving the country with a tour group in January 2016.
At a press conference before his trial, a sobbing Warmbier said he had made "the worst mistake of my life" and pleaded to be released.
The North has occasionally jailed US citizens and released them only after visits by high-profile political figures, including former p
Meanwhile, the White House said Moon and Trump will meet on June 29 and 30 to discuss ways of building what America frequently calls
Moon, a centre-left politician who was sworn in last month after a landslide election win, wants to engage with the North to bring it to the negotiating table, rather than continuing the hardline stance taken by his ousted predecessor Park Geun-Hye.