North Korea has dropped its demand that the U.S. remove troops from South Korea before it gives up its nuclear weapons, and has said it wants to “denuclearize completely,” according to South Korean President Moon Jae-in.

North Korea has cited the 28,500 U.S. troops stationed in South Korea as part of its justification for developing nuclear weapons, and has called for Washington to withdraw those troops if it wanted a denuclearized Korean Peninsula.

But Moon told reporters Thursday that North Korean leader Kim Jong Un has not attached any conditions the U.S. would object to, clearing a path for negotiations between Washington and Pyongyang to continue.

“North Korea is expressing a willingness to denuclearize completely,” Moon told reporters Thursday, according to reports.

“The North Koreans did not present any conditions that the United States could not accept, such as the withdrawal of American troops from South Korea,” he said. “They only talk about an end of hostilities against their country and about getting security guarantees. It’s safe to say that the plans for dialogue between the North and the United States could proceed because that has been made clear.”

The Trump administration is preparing for a historic summit with North Korea, which is expected to occur in May or June. The meeting will mark the first time a sitting U.S. president will meet with a North Korean leader.

Ahead of the meeting, CIA Director Mike Pompeo traveled to North Korea at the beginning of April for a secret meeting with Kim. President Trump tweeted Wednesday the meeting “went very smoothly” and the two formed a “good relationship.”

The president told reporters a “bright path” is available to North Korea if the country “achieves denuclearization in a completely verifiable and irreversible way.”

But Trump warned he is prepared to walk away from his upcoming meeting with Kim if the U.S. doesn’t believe the sit-down will be successful.

“If the meeting, when I’m there, is not fruitful, I will respectfully leave the meeting and continue what we’re doing,” the president said during a joint press conference with Japanese Prime Minister Shinzo Abe.