South Korea's presidential envoy Hong Seok-hyun met with U.S. Senate Armed Services Committee Chairman John McCain on Friday to outline the policy of President Moon Jae-in on the alliance with the U.S., North Korea and other issues.

Hong was also scheduled to meet later Friday with House Armed Services Committee Chairman Mac Thornberry as part of a series of meetings he has been holding since arriving in Washington on Wednesday on a mission to reaffirm and further strengthen the alliance under the Moon administration.

Upon arrival, Hong paid a visit to President Donald Trump at the White House. During the meeting, Trump expressed hope for working closely together with Moon to strengthen the alliance and resolve the North Korean nuclear issue.

On Thursday, Hong held a meeting with Secretary of State Rex Tillerson for talks mainly on how to deal with the North Korean nuclear issue. Hong quoted Tillerson as saying that he wants the North to trust the U.S. promise of no hostility and refrain from nuclear or missile tests.

The envoy also held meetings with congressional leaders such as Rep. Ed Royce (R-CA), chairman of the House Foreign Affairs Committee; Rep. Ted Yoho (R-FL); Sen. Ben Gardin (D-MD), ranking member of the Senate Foreign Relations Committee; and Sen. Cory Gardner (R-CO), chairman of the Senate Foreign Relations Subcommittee on East Asia.

Details of Hong's meeting with McCain were not immediately available, but the deployment of the U.S. THAAD missile defense system was believed to be among the key topics as McCain has been a vocal critic of retaliatory measures China has taken against South Korea for hosting the system that Beijing claims hurts its security interests.

During the campaign, Moon was critical of his predecessor's decision to host THAAD, saying that the decision was made without due process to collect public opinion. Presidential aides say the stance does not necessarily mean Moon is opposed to the deployment.

Trump fueled opposition to THAAD among the South Korean public by demanding the South pay for the $1 billion system. The demand runs counter to a deployment agreement in which the U.S. agreed to pay for the system if the South agreed to host it and provide land.

Also Friday, Hong held a breakfast meeting with experts from the Center for Strategic and International Studies (CSIS) as well as a lunch meeting hosted by the Heritage Foundation. He also met with editors of the Washington Post.

Hong is scheduled to head back to Seoul on Saturday.

(Yonhap)