Seoul, Nov 15 : South Korea and the US staged joint air drills on Wednesday, involving two US B-52H strategic bombers, over the Yellow Sea, Seoul's Defense Ministry said, in the latest show of force against North Korea. South Korean F-35A, F-15K and US F-35B and F-16 fighter jets escorted the nuclear-capable bombers during the drills, the Ministry said, as the allies seek to bolster security cooperation against growing North Korean military threats. The exercise marked the key US military asset's return to the peninsula in less than a month after it made its first-ever landing at a South Korean air base on October 17, Yonhap news agency reported. With the latest exercise, South Korea and the US have staged seven combined air drills, involving the B-52H bomber, over the peninsula this year. They have staged 12 such exercises this year with US strategic bombers in total, including the B-1B bomber, which is no longer nuclear-capable. The frequent deployments of high-profile military assets this year come amid US efforts to bolster its security commitment to South Korea against evolving nuclear and missile threats from North Korea. During annual bilateral security talks on Monday, US Secretary of Defence Lloyd Austin reaffirmed America's extended deterrence commitment to using the full range of its military capabilities, including nuclear weapons, to defend its ally. "In line with this commitment, this exercise expands the frequency and intensity of the deployment of US strategic assets to demonstrate an effect equivalent to constant deployment," the Ministry said, describing the drills as "extended deterrence in action". On Monday, Austin also hailed the B-52's first landing in South Korea as "a milestone" for the US deterrence efforts and unveiled there will be "another carrier battle group that comes soon". According to sources, the USS Carl Vinson nuclear-powered aircraft carrier is expected to dock at the Busan naval base early next week. /IANS