President Donald Trump met with Kim Jong-un to discuss the denuclearization of North Korea on June 12. This historic summit marks the first time a United States President has met face-to-face with the leader of North Korea.

“We had a really fantastic meeting, a lot of progress, really very positive,” Trump said, according to The Wall Street Journal. “I think better than anybody could have expected—top of the line.”

After the meeting, President Trump said he was very hopeful that his relationship with Kim would continue to improve, according to The Wall Street Journal.

The Wall Street Journal also reported that Kim likewise recognized the significance of this relationship. “Old prejudices and practices worked as obstacles in our way forward, but we overcame all of them and we are here today,” Kim said, according to The Wall Street Journal.

After the meeting, Trump and Kim sat down to sign a document regarding the terms of North Korea’s denuclearization. As the United State’s part of the deal, joint military exercises between the U.S. and South Korea will be discontinued.

“Over here, in our country, some people would rather see this historic deal fail than give Trump a win, even if it does save potentially millions & millions of lives,” said Trump on his Twitter account Sunday.

According to The Wall Street Journal, many critics of Trump’s nuclear deal with Kim say the terms for the deal are too vague and that it doesn’t account for procedures such as inspections of North Korean nuclear stations.

According to The Wall Street Journal, leaders in Japan and South Korea are concerned with Trump’s promise to end military exercises in South Korea. Japan’s defense minister, Itsunori Onodera, said that these joint exercises are a critical peacekeeping tool in Asia.

Later, a White House official clarified the promise Trump made to Kim by saying that regular training and drills would continue to take place with the U.S. and South Korean militaries. The major joint exercises will be the only military activity to discontinued. This will change how the U.S. interacts with both North and South Korea and may have future implications on South Korean’s seeking to travel to the U.S., including students.