The timing of a planned switch of US wartime command to South Korean forces is "not that important," a top US military officer said Tuesday.

In the case 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 agreement, the United States would transfer full operational control to South Korea in 2015 but Seoul has asked to postpone the transition. A deadline for 2102 was already delayed.

Admiral Samuel Locklear, head of US Pacific Command, which oversees all American forces in the region, sought to play down the significance of the timing at a news conference and did not say if the handover would go ahead as scheduled.

"But as we are moving toward 2015, it will be based on what the conditions are at that time," Locklear said.

"What we don't want to do is to delay ensuring that we have the right things in place to make sure the alliance is as viable as it can be in the future, waiting on some decision about OPCON (operational control) transfer, because it's really not that important of a decision," he said.

More important were decisions about the organizational structure of South Korea's army and "how do we equip and man that organizational structure to be successful," he said.

While the US-South Korea "alliance has never been stronger," the four-star admiral said there were continued investments needed by both sides to make sure forces had "credible" hardware and "command and control."

The date for shifting wartime command to Seoul has become a political issue in South Korea, and North Korea's hostile rhetoric, rocket tests and unpredictable behavior in recent years has prompted calls to put off the transfer.

During a visit to South Korea in October, US Defense Secretary Chuck Hagel did not indicate any decision on the handover and said the two countries would continue to hold talks on the plan.

The current arrangement that would have the US military command all troops in the South in the event of a war has been in place since the end of the Korean war 60 years ago.