BRUSSELS (Reuters) - NATO Secretary-General Anders Fogh Rasmussen will travel to South Korea this week, the alliance said on Tuesday, at a time when North Korea has intensified threats of an imminent conflict against the United States and the South.

A NATO official said Rasmussen's April 11-13 visit to South Korea, which will be followed by a trip to Japan, was long scheduled and not linked to the situation in North Korea.

(Reporting by Adrian Croft; Editing by Justyna Pawlak and Jon Hemming)