Tony Kim. Kim Hak-song. Kim Dong-chul.

Those are the names of three American hostages North Korea held for months — and just agreed to release. They’re accompanying Secretary of State Mike Pompeo, who was in North Korea for official meetings, back to the United States, according to President Donald Trump.

Last week, in what was seen as a diplomatic gesture in advance of upcoming talks between Trump and North Korean leader Kim Jong Un, the North Korean government transferred the Americans from the brutal labor camps where they were being held to a hotel near Pyongyang.

Then late Tuesday night, Kim took the final step, authorizing their official release and handing them over to US custody, which Trump confirmed on Twitter Wednesday morning.

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

Trump added in a following tweet that Pompeo and the three former hostages will arrive in the US at 2 am on Thursday. Trump will greet them once they land.

This moment was at least two months in the making. In March, North Korean Foreign Minister Ri Yong Ho traveled to Sweden — which acts as an intermediary for Washington and Pyongyang — to discuss releasing the hostages. And over Easter weekend, then-CIA Director Pompeo spoke personally with Kim about the detainees.

Former New Mexico Gov. Bill Richardson, who has spent decades negotiating hostage releases with North Korea, told me the releases might form part of a larger negotiating process. “I believe the US made it a precondition that North Korea release American hostages before the summit,” he said during a May 4 interview.

Experts believe that freeing the three men would be a tangible way for North Korea to try to lower tensions with the US before what would be a historic summit. That’s especially true given the lingering ill will between Washington and Pyongyang over North Korea’s treatment of Otto Warmbier, a 22-year-old American who was detained by the Kim government for 17 months and died under mysterious circumstances shortly after he was brought home to the US.

“Releasing the three Americans is a good sign that North Korea wants a good meeting between President Donald Trump and Kim Jong Un and, eventually, a peaceful resolution of the nuclear and other issues with North Korea,” says Joseph DeTrani, a former intelligence official who previously negotiated peace talks with North Korea.

That means a possible hostage release could form part of a longer rapprochement between America and North Korea. But make no mistake: Getting US citizens out of North Korean prisons — which one report said were “as terrible [as] Nazi camps” — is a big win for the men’s families, and for Trump himself.

Who are the US hostages that were held in North Korea?

Here’s what we know about the three US hostages headed home right now. One was snatched during the Obama presidency, while the other two were taken into custody after Trump took office.

Tony Kim, who reportedly is 59 years old, spent a month last year teaching at the Pyongyang University of Science and Technology. But as he boarded a plane on April 22, 2017, to leave North Korea, authorities arrested him on unknown charges. Kim, who was originally from South Korea but later became a US citizen, lived in North Korea with his wife, who reportedly still lives in the country.

“We miss him. We want to know how he is doing. We want to see him, and ultimately we want to have him home,” Sol Kim, Tony’s son, told the Washington Post in February.

Kim Hak-song also worked at the Pyongyang University of Science and Technology. North Korean authorities arrested him in early May, two weeks after snatching Tony Kim, for committing what the North Korean state media described as “hostile acts.” It’s unclear if their detainments are connected in any way.

Kim, originally from China, is an agricultural consultant who came to America in the 1990s and later earned US citizenship. He then moved back to China to study agriculture and, later, moved to Pyongyang.

The longest-imprisoned American in North Korea is Kim Dong-chul, in his mid-60s. North Korean authorities arrested him in October 2015 and later sentenced him to 10 years of hard labor for espionage and subversion.

Kim lived in a Chinese city near the border with North Korea and had worked as the head of a hotel services company in the special economic zone between the two countries since 2001.

North Korean prisons are notoriously brutal, and it’s not yet clear what condition the men are in. The hope, though, is these hostages will escape the fate of Warmbier, the college student who was detained in North Korea and died soon after being released.

At least one American hostage already died because of North Korea

The Warmbier case is mysterious, and grim.

North Korea imprisoned him in January 2016, and two months later, he was sentenced to 15 years of hard labor for committing an unspecified “hostile act” against North Korea. After 17 months in North Korea, the Trump administration secured his release on June 13, 2017 — but he returned home in a coma and died six days later after sustaining brain injuries.

His parents say he was “systematically tortured” to death and late last month sued the North Korean government for its treatment of their son. North Korea denies torturing Warmbier, and a US coroner report last September found no obvious signs of torture.

The Trump administration has stood by the Warmbiers and used the tragedy of their son’s death to highlight just how cruel the Kim regime is.

Trump invited the Warmbiers to his State of the Union address. The president noted what North Korea did to Otto during the speech while also highlighting the Warmbiers’ grief and resolve. Vice President Mike Pence invited Fred Warmbier, Otto’s father, to the 2018 Olympics in Pyeongchang, South Korea. Having Warmbier by the vice president’s side during such a global event — just 50 miles away from the border with North Korea — was quite the act of defiance by both the administration and the Warmbier family.

Beyond the Warmbier case, the Trump administration seems to have made freeing US hostages held abroad more of a priority, and it has unquestionably had more success than the Obama administration.

The Trump administration worked with Egypt to release Aya Hijazi, an Egyptian-American aid worker, from captivity in April 2017. And last October, Trump announced the release of Caitlan Coleman, her husband, and the three children that they bore in a captivity that lasted five years.

In 2015 — six years into his presidency — then-President Obama admitted his administration had at times failed families of hostages. “It is true that there have been times where our government, regardless of good intentions, has let them down,” Obama said. “I promised them that we can do better.”

Trump, it seems, is following through on that promise — to the joy of the hostages and their families.