SEOUL, Jan. 11 -- Militaries of South Korea and the United States are continuing discussion on additional deployment of "strategic assets" on the Korean peninsula, a day after a U.S. B-52 bomber flew over South Korea, Seoul's defense ministry said Monday.

Defense Ministry spokesman Kim Min-Seok told a routine press briefing that Seoul and Washington are closely and continuously discussing an issue on deploying other strategic assets in addition to the B-52 bomber that flew over South Korea on Sunday.

The B-52 bomber, capable of delivering nuclear missile, returned to its base in Guam after flying over the air base in Osan, 40 km south of Seoul, in response to the Democratic People's Republic of Korea (DPRK)'s fourth nuclear test.

The DPRK said last Wednesday that it had successfully tested its first hydrogen bomb, the fourth in total. Previous tests were conducted in 2006, 2009 and 2013 respectively.

Other strategic assets reportedly include a U.S. aircraft carrier, a U.S. nuclear-powered submarine and F-22 stealth fighters.

The U.S. aircraft carrier Ronald Reagan, currently in Yokosuka, Japan, is widely expected to be deployed on the peninsula during the U.S.-South Korea joint annual war games scheduled to kick off in February.

After the DPRK carried out its third nuclear test in February 2013, the U.S. military sent its strategic assets to the peninsula in retaliatory measures.