The U.S. envoy on the North Korean nuclear program will visit South Korea next week as part of his Asian tour, a diplomatic source here said Thursday, as the leaders of Seoul and Washington vowed no concessions to Pyongyang after months of simmering tensions.

U.S. Special Representative for North Korea Policy Glyn Davies plans to arrive in Seoul on May 13 for a three-day stay as part of his trip to Asia which also includes China and Japan, the source said, requesting anonymity.

During the visit, Davies plans to meet his South Korean counterpart Lim Sung-nam and other officials in Seoul, he added. 

Another source told Yonhap News Agency on Wednesday that Lim and Davies are expected to "share their assessments of the current situation on the Korean Peninsula following the summit between President Park Geun-hye and U.S. President Barack Obama and discuss a full range of North Korea issues."

The two sat down for talks in Washington earlier this week and discussed issues of mutual concern, including how to deal with North Korea. (Yonhap News)