The head of the U.S. military's Pacific Command (PACOM) arrived in Seoul on Sunday, the South Korean Defense Ministry said as the two allies readied for the start of an annual large-scale military exercise Monday amid soaring tensions with nuclear-armed North Korea.

PACOM commander Adm. Harry Harris attended a change-of-command ceremony for new South Korean Joint Chiefs of Staff Chairman Jeong Kyeong-doo and later met with Defense Minister Song Young-moo to discuss responses to the North Korean threat, the Yonhap news agency quoted the Defense Ministry as saying.

Harris was scheduled to view the joint Ulchi Freedom Guardian (UFG) exercise during the trip that will run through Tuesday.