In Light of North Korea Threat, South Asks U.S. to Retain Command of All Forces Past 2015.

South Korea has asked the U.S. to consider delaying the planned 2015 transfer of wartime control of South Korean forces to Seoul's command because of North Korea's nuclear threat, the country's defense ministry said Wednesday.

Under existing plans, South Korea is slated to gain by December 2015 full command of its own armed forces in the event of war. The U.S. has assumed this responsibility since the end of hostilities in the Korean War in 1953.

If a postponement is agreed upon, it would be the second delay in the transition's schedule. The two sides decided in October 2010 to push back the original April 2012 deadline after the sinking of a South Korean navy ship. North Korea denied responsibility for that attack.

While there are no discussions of removing U.S. forces, the American control over South Korean military has been considered the most stable guarantor of security on the Korean Peninsula. Officials in Seoul and some former commanders of U.S. troops in Korea have voiced concerns that a change in the command structure could destabilize the South's deterrence against the continued threat from the North.

Tensions between the Koreas escalated earlier this year after the North's February nuclear test as Pyongyang warned of possible nuclear attack against the U.S. and the South.

The U.S. has 28,500 troops stationed in South Korea. The American four-star general and commander of the U.S. Forces on the peninsula heads a structure called U.S.-Republic of Korea Combined Forces Command, which directs both countries' troops in the event of war. A four-star South Korean general has served as deputy commander.

The combined structure commands more than 600,000 active-duty service members from both armed forces in peacetime. If a war were to break out, U.S. forces deployed from other parts of the world as well as 3.5 million South Korean reservists would also fall under this command.

In their annual joint military exercises in March, South Korean and U.S. troops were directed by the South Korean Joint Chiefs of Staff for the first time, part of planned steps toward an eventual handover of command.

The ministry said the lead-up to the transfer was still based on command transfer plans set in 2010.

"The government will pursue the OPCON transfer with a priority focus on robust security," the ministry's statement said.

This year, South Korea has reinforced its independent arsenal, including the acquisition of attack helicopters in April from the U.S. Army. It also has plans for fighter jet upgrades, although the are temporarily suspended following disagreements over the pricing suggested by American and European defense contractors.

A spokesman for the U.S. Forces Korea declined to comment and said any decision over a delay would come from the U.S. Department of Defense.