US President Trump has condemned the brutality of the North Korean regime following Warmbier's passing.
But the trip made last week by Joseph Y. Yun, the top United States envoy on North Korea, was starkly different.
Trump's administration talked up the threat of war earlier this year, sending aircraft carrier strike groups to the region and holding military exercises with allies Japan and South Korea.
Since then, things had appeared to calm down. It's unclear exactly how many Americans go to North Korea every year.
In a sign that U.S. "Otto's father is right: travel propaganda lures far too many people to North Korea".
Secretary of State Rex Tillerson also said in a statement that the US holds North Korea accountable for Warmbier's "unjust imprisonment, and demand the release of three other Americans who have been illegally detained". "What makes China take steps is a missile or nuclear test, not the death of an American student", he said.
In a tearful statement of apparent confession, Mr Warmbier said he had tried to take it as a "trophy" for an American church.
Kim reportedly studied at a university in California and became a USA citizen in the 2000s before moving back to China, where he was born, 10 years later.
Trump confirms he's under investigation, fires angry tweets
Rosenstein took over the investigation into whether Russian Federation tried to tip the U.S election in favour of Mr. The Department of Justice has a long established policy to neither confirm nor deny such allegations.
Mr Spicer said the Trump administration would "continue to work with [China] and others to put the appropriate pressure on North Korea".
A man who identified himself as Kim Dong-chul attends a news conference in Pyongyang in this undated photo released by North Korea's Korean Central News Agency on March 25, 2016.
Trump has delivered conflicting rhetoric on North Korea and its leader, whom he has called a "madman with nuclear weapons".
"I'm asking the USA or South Korean government to rescue me", he told CNN.
"It has been 10 years since we were serious about North Korea sanctions and it is not too late to increase the pressure on Beijing and Pyongyang to protect the United States and its allies from the risky Kim regime", said Anthony Ruggiero, a sanctions specialist and senior fellow at the Foundation for Defense of Democracies. The secret negotiations over Warmbier's release are some of the only known direct contacts between the nations in recent years. They said it might not be possible to detect any sign of it after so many months. "It's really misconstrued that China is responsible for everything that happens between Washington and Pyongyang".
His parents told The Associated Press in a statement the day of his release that they wanted "the world to know how we and our son have been brutalized and terrorized by the pariah regime " and expressed relief he had been returned to "finally be with people who love him". Earlier this month, Moon temporarily halted the installation of a US missile shield pending an environmental impact assessment.
The government of China, North Korea's main ally, said Warmbier's death was a tragedy.
Adrian Webster, a 31-year-old Australian who traveled to North Korea with his girlfriend in April, said that he always felt safe with Young Pioneer Tours.
Warmbier's parents released a statement Monday criticizing North Korea for the death of their son. I believe it is quite clear that they have a heavy responsibility in the process that led to Mr Warmbier's death.
"These flights with Japan and the Republic of Korea (ROK) demonstrate solidarity between Japan, ROK and the U.S. to defend against provocative and destabilizing actions in the Pacific theater", a USA military official told CNN. "There is no possibility of it".