US diplomat heads to Tokyo, Seoul

Official's visit comes amid security concerns in the Korean Peninsula

US Assistant Secretary of State Kurt Campbell is expected to visit Tokyo on Thursday and Seoul later this week, following a series of recent visits by high-ranking US officials to East Asia, where security uncertainties have raised concerns.

Recent developments on the Korean Peninsula and the territorial row between China and Japan - a close ally of the US in this region - over the Diaoyu Islands will be on top of Campbell's agenda, analysts said.