US Secretary of State John Kerry will visit to South Korea next month as part of his Northeast Asia tour, the US State Department said on Thursday.Following the G-8 meetings in London from April 10-11, Kerry plans to visit South Korea, Japan and China, according to department spokeswoman Victoria Nuland. It will mark his first trip to the region since he took office in February, according to Yonhap.“The secretary will meet with counterparts and discuss the full range of bilateral, multilateral and regional issues as well as our economic cooperation and the environment,” she said at a press briefing.In Seoul, Kerry will meet with President Park Geun-hye and Foreign Minister Yun Byung-se to discuss the North Korea problem and bilateral alliance issues, added the source.Separately, U.S. Deputy Secretary of Defense Ash Carter will travel to South Korea later this month, Pentagon Press Secretary George Littles said.