US and South Korean officials agreed Thursday to delay transfer of the Pentagon's control of Korean troops in the event of war with the North, with no new transfer date set.

Defense Secretary Chuck Hagel said after meeting with South Korean Defense Minister Han Min-Koo that their memorandum of understanding outlined a "conditions-based process" for the transfer instead of relying on a timeline.

In the event of war with North Korea, current plans call for an American military commander to lead the 28,500 US troops deployed in South Korea as well as that country's 640,000-strong force.

Under an alliance pact, the United States was to transfer full operational control to South Korea in 2015 but Seoul asked to postpone the transition. A deadline for 2012 was already delayed.

"While this agreement will delay the scheduled transfer of operational control, it will ensure that when the transfer does occur, Korean forces have the necessary defensive capabilities to address an intensifying North Korean threat," Hagel told reporters at the Pentagon, with Han at his side.

South Korea had been scheduled to take wartime control, known as OPCON, by the end of next year, but now "no new date for transferring OPCON will be set," the Pentagon said in a statement.

North Korea's hostile rhetoric, rocket tests and unpredictable behavior in recent years has prompted calls to put off the transfer, and Han pointed to such threats in calling for continued security vigilance.

"North Korea is continuing to launch new types of provocations, including an additional nuclear test, development of new tactical missiles, infiltration by miniature UAVs (unmanned aerial vehicles) and machine gun fire," he said.

"As such the security situation on the Korean peninsula is more precarious than ever."

Hagel and Han met at the Pentagon as part of the 46th annual Security Consultative Meeting, in which the allies discussed their ongoing military cooperation.

"Our alliance commitments are as important as ever, because North Korea's destabilizing policies and dangerous provocations continue to pose a grave threat to security and stability in Northeast Asia and around the globe," Hagel said.