Last summer, 22-year-old American student Otto Warmbier returned to the US after being held captive in North Korea for 17 months — and a few days later, he died due to health complications.

At the time, President Donald Trump swiftly condemned North Korea for failing to “respect the rule of law or basic human decency” and slammed the “brutality” of its regime.

But at a welcoming ceremony for three American captives just released from North Korea early Thursday morning, Trump struck a very different tone.

“We want to thank [North Korean leader] Kim Jong Un, who really was excellent to these three incredible people,” Trump said at Joint Base Andrews outside Washington.

Trump’s cheerful language regarding the treatment of the former captives was shocking. The former captives had been imprisoned for a year or longer and accused of charges ranging from espionage to “hostile acts.” One of the men had even been sentenced to 10 years’ hard labor in a nation that hosts some of the world’s most brutal prisons.

Trump’s warm rhetoric toward Kim also stands in stark contrast to the belligerent language he used toward the North Korean leader just months ago. In September at the United Nations General Assembly, Trump said Kim was “on a suicide mission” and threatened to “totally destroy North Korea.”

But his comments on Thursday serve as a reminder that Trump’s perception of world leaders can be heavily swayed by symbolic positive gestures — and that Kim’s release of the prisoners could be an attempt to soften up Trump ahead of the two leaders’ upcoming summit, which will be held in Singapore in June.

Kim seems to be making a big impression with his decision to release the hostages

Trump’s reaction to North Korea’s release of the three Americans has been one of unbridled excitement. The president told reporters on Wednesday that “everyone thinks” he deserves a Nobel Peace Prize for securing their release, but “the prize I want is victory for the world.”

At the official event welcoming the former prisoners home, Trump sounded notably optimistic about the future of US-North Korean relations. “Hopefully everything is going to work out at the highest level,” he said.

But his description of Kim as being “excellent” to the prisoners didn’t seem to match up with their experiences. When asked by a reporter about how he was treated, Kim Dong-chul replied, after a long pause, “We were treated in many different ways. For me, I had to do a lot of labor. But when I got sick, I was also treated by them.”

North Korean authorities arrested Kim in October 2015 and later sentenced him to 10 years of hard labor for espionage and subversion.

Tony Kim, one of the other captives, spent a month last year teaching at the Pyongyang University of Science and Technology. But as he boarded a plane in April 2017 to leave North Korea, authorities arrested him on unknown charges.

The third captive, Kim Hak-song, also worked at the Pyongyang University of Science and Technology. North Korean authorities arrested him in early May, two weeks after detaining Tony Kim, for committing what the North Korean state media described as “hostile acts.”

The status of their health is unclear, but they certainly seem to be in better shape than Warmbier, who returned to the US in a vegetative state and showed signs of extensive brain damage. Human rights watchdogs have documented systematic torture, starvation, and forced labor in North Korean prisons for many years.

As the US and North Korea head toward a historic summit to discuss a solution to their impasse over North Korea’s nuclear program, calmer rhetoric is to be expected. But what’s concerning is that Trump could swing too hard in the opposite direction at a time when he needs to stay disciplined for negotiations.