US secretary of state secures release of US detainees after meetings with North Korean officials in Pyongyang.

North Korea released three US citizens from prison following a visit to Pyongyang by Secretary of State Mike Pompeo in advance of an historic meeting between both countries’ leaders.

The three Americans appear in “good health”, US President Donald Trump said in a tweet on Wednesday.

Trump added the time and date for the future meeting between himself and North Korean leader Kim Jong-un had been “set”.

The three men travelled back to the US alongside Pompeo, who was in Pyongyang to arrange the planned US-North Korea nuclear summit. They’re expected to arrive at Andrews Air Force Base in Maryland early Thursday.

Trump said he will “be there to greet them”.

I am pleased to inform you that Secretary of State Mike Pompeo is in the air and on his way back from North Korea with the 3 wonderful gentlemen that everyone is looking so forward to meeting. They seem to be in good health. Also, good meeting with Kim Jong Un. Date & Place set. — Donald J. Trump (@realDonaldTrump) May 9, 2018

A White House statement on Wednesday said Trump appreciated Kim’s decision to free the Americans and views it as “a positive gesture of goodwill”.

The US had frequently called for the release of the three prisoners, all of whom are Korean-American nationals, with their detention widely seen as being politically motivated.

Kim Dong-chul, Tony Kim, and Kim Hak-song had been held by North Korea for periods ranging between one and two years over alleged anti-state activities.

“We want to thank all of those who have worked toward and contributed to his return home,” said the family of Tony Kim.

“We also want to thank the president for engaging directly with North Korea. Mostly, we thank God for Tony’s safe return,” the family said in a statement.

Pompeo, who has visited North Korea twice in the last six weeks, said on Wednesday he was “delighted” to bring home the three men following “productive meetings in Pyongyang with Chairman Kim Jong-un”.

I had productive meetings in Pyongyang with Chairman Kim Jong-un and made progress. I'm delighted to bring home three Americans. — Secretary Pompeo (@SecPompeo) May 9, 2018

Trump said he will announce the site for the summit with Kim within three days and it will not be held at the demilitarised zone along the border between the two Koreas.

“It will not be there,” he told reporters at the White House on Wednesday when asked if the planned meeting would be at the DMZ. “We’re going to announce it within three days.”

Warming relations

The prisoners’ release marks the latest development in improving US-North Korea relations in the run-up to Trump and Kim’s summit.

Al Jazeera’s Diplomatic Editor James Bays, reporting from the UN headquarters in New York, said North Korea’s decision was an important part of the “diplomatic and political choreography” being carried out before Trump and Kim’s meeting.

“Diplomats have told me they could see no way that the summmit could take place until this release had taken place,” Bays said.

“[They said] it would be impossible for a US president to sit down with a North Korean leader while that leader was holding three Americans. They saw this move as a prerequisite for the summit.”

The US troop presence in South Korea would not be part of discussions on de-nuclearisation with North Korea, the US defence chief Jim Mattis said on Wednesday.

“That’s not something that would be on the table in the initial negotiation,” Mattis told a Senate hearing, describing the 28,500 US military forces on the Korean Peninsula as a “stabilising presence”.

Expectations of a meeting between the two leaders follow months of angry exchanges over Pyongyang’s testing of nuclear weapons and long-range missiles, including some theoretically capable of reaching the US mainland.

A surprising about-turn by Kim in recent weeks, however, has lessened tensions on the Korean Peninsula.

Last month, Kim and South Korean leader Moon Jae-in pledged to formally end the 1950s Korean War and pursue “complete denuclearisation” of the peninsula in the first inter-Korea summit since 2007.

The two leaders signed a joint statement that committed both to deepening ties and working towards reunification after the meeting on April 27, which saw Kim become the first North Korean leader to set foot in South Korea since the Korean War.