WASHINGTON (AP) — Three Americans detained in North Korea for more than a year are on their way back to the U.S. with Secretary of State Mike Pompeo, President Donald Trump announced Wednesday in the latest sign of improving relations between the two longtime adversary nations.

Trump said on Twitter that Pompeo was “in the air” and was with “the 3 wonderful gentlemen that everyone is looking so forward to meeting.” The president, who had been hinting about an imminent release, said he would greet them at Andrews Air Force Base at 2 a.m. Thursday.

The release of the detainees came as Pompeo visited North Korea on Wednesday to finalize plans for a historic summit between Trump and the North’s leader, Kim Jong Un. Trump said on Twitter that there had been a “good meeting with Kim Jong Un,” adding: “Date & Place set.”

North Korea had accused Kim Dong Chul, Kim Hak Song and Tony Kim, all Korean-Americans, of anti-state activities but their arrests were widely seen as politically motivated and had compounded the dire state of relations over the isolated nation’s nuclear weapons.

The family of Tony Kim thanked “all those” who worked for his return and also credited Trump for engaging directly with North Korea. “Mostly we thank God for Tony’s safe return,” the family said in a statement, and they urged people to “continue to pray for the people of North Korea and for the release of all who are still being held.”

White House spokeswoman Sarah Huckabee Sanders said in a statement that Trump viewed the release “as a positive gesture of goodwill.”

The three had been held for periods ranging between one and two years. They were the latest in a series of Americans who have been detained by North Korea in recent years for seemingly small offenses and typically freed when senior U.S. officials or statesmen personally visited to bail them out.

The last American to be released before this, college student Otto Warmbier, died in June 2017, days after he was repatriated to the U.S. with severe brain damage.

Warmbier was arrested by North Korean authorities in January 2016 for stealing a propaganda poster and sentenced to 15 years in prison with hard labor. His parents have filed a wrongful death lawsuit, accusing the government of torturing and killing their son.

Of the newly released detainees, Kim Dong Chul, a South Korean-born U.S. citizen, had been held the longest. The former Virginia resident was sentenced in April 2016 to 10 years in prison with hard labor after being convicted of espionage. He reportedly ran a trade and hotel service company in Rason, a special economic zone on North Korea’s border with Russia.

The other two detainees hadn’t been tried.

Kim Hak Song worked in agricultural development at an experimental farm run by the Pyongyang University of Science and Technology, or PUST. The university is the only privately funded college in North Korea and was founded in 2010 with donations from Christian groups. He was detained last May for alleged anti-state activities.

Tony Kim, who also uses the name Kim Sang-duk, was detained in April 2017 at the Pyongyang airport. He taught accounting at PUST. He was accused of committing unspecified criminal acts intended to overthrow the government.

Pompeo, in his visit, discussed the agenda for a potential Trump-Kim Jong Un summit in a meeting with Kim Yong Chol, vice chairman of the central committee of North Korea’s ruling party.