President Trump suggested late Wednesday that three Americans held in North Korea could be freed soon.
"As everybody is aware, the past Administration has long been asking for three hostages to be released from a North Korean Labor camp, but to no avail. Stay tuned!" the president tweeted.
His remarks come ahead of a possible historic summit between him and North Korean leader Kim Jong Un.
Trump was apparently referring to Tony Kim, also known as Kim Sang-duk, an American teacher detained by North Korea in April 2017; Kim Hak-song, also known as Jin Xue Song, whose detention was announced the following month; and Kim Dong Chul, who was arrested in 2015.
The three are believed to be in a North Korean labor camp.
Tony Kim, a U.S. citizen in his late 50s briefly taught accounting at Pyongyang University of Science and Technology, or PUST, the only privately run university in the country — funded largely by evangelical Christians in the United States and China, USA Today reports. He was accused of unspecified "hostile acts."
Kim Hak-song also worked at PUST and was detained on a similarly vague charge of "hostile acts" against North Korea.
The third detainee, 60-something Kim Dong Chul, of Fairfax, Va., was sentenced to 10 years in prison and hard labor in April 2016.
USA Today writes, "A month before his trial, he supposedly apologized for trying to steal military secrets for South Koreans. He had been living in Rason, North Korea, in a special economic zone where he ran a trading and hotel services company."
Secretary of State Mike Pompeo — who secretly visited North Korea last month when he was still head of the CIA — is said to have discussed the plight of the three Americans with North Korean leader Kim.
Meanwhile, National Security Adviser John Bolton said release of the Americans would be a "demonstration of their sincerity" in the lead-up to the summit, according to The Associated Press.
Last year, North Korea released American Otto Warmbier, a university student who was detained at the Pyongyang airport in January 2016 while on a five-day tour of North Korea. He was later convicted of stealing a propaganda poster.
He was subsequently sentenced to 15 years hard labor, but then released 15 months later, in June 2017, gravely ill and in a coma. He died soon after his return to the United States.
North Korea also freed U.S. citizens during visits by former Presidents Bill Clinton, in 2009, and Jimmy Carter, in 2010.