Less than a week after talks between United States President Donald Trump and North Korea’s Kim Jong Un in Hanoi collapsed, South Korea’s special envoy left Seoul in route to the United States. Lee Do-hoon will meet with Stephen Biegun in Washington. Both are top nuclear negotiators.

The reason for Lee’s dispatch is unknown, but it is speculated that Lee may want to learn more about the talks that Trump and Kim Jong Un had when in Hanoi.

Trump claimed that there was a “mega settlement” in the works before the meeting, and he had also said that it was a “big deal.”

Lee will analyze the results from the last summit and discuss future plans with U.S. counterparts.

Meetings will take place until Thursday in the United States in Washington. Diplomatic channels will be used in the discussions. The failure of the summit resulted in President Moon Jae-in calling national security council members for a meeting.

Moon has been a supporter of discussions with North Korea, which have also heavily involved the United States. He is asking an array of former and current officials from all three countries to come together to help bring more stability to the region.

Trilateral talks will not be the focus of Kim’s deployment this week, according to sources.

South Korea and the United States have been working on increasing relations with North Korea, most recently cancelling major war games in an effort to support diplomatic relations. The collapse of the talks between the United States and North Korea were a major blow to many South Koreans who are seeking peace with North Korea. The failure of the summit will cause South Korea’s plans to be pushed back further.

South Korea and the United States have had strong ties for decades, with Korean immigrations to the United States being driven by military relations, politics and economics. The two have been strong partners since restrictions on Asian immigration were lifted in 1965. South Korea accounts for the majority of the 1 million Korean immigrants that were reported in the United States in 2015.

Immigrating to the United States from South Korea has started to reverse in trends, with the population shrinking from 1.1 million to 1 million between 2010 and 2015. There are also fewer students applying for student visas from South Korea, dropping 4% from 64,000 to 61,000 between the 2014-2015 school year and the 2015-2016 school year.