This photo, provided Friday, shows an F-4E fighter jet firing an air-to-air missile during live-fire drills over waters off the west coast from Monday to Friday. (Air Force)

South Korean and US warplanes staged a combined live-fire exercise against North Korean cruise missile and long-range artillery threats in waters off the west coast this week, the South's Air Force said Friday.

The five-day drills began Monday, mobilizing some 40 aircraft, including South Korean F-35A, F-15K and F-4E jets, as well as A-10 and F-16 aircraft from the US 7th Air Force stationed in the country.

Pilots trained on staging precision strikes against simulated enemy cruise missiles flying at low altitudes with air-to-air missiles and against long-range artillery, using air-to-surface missiles and guided bombs, the Air Force said.

The drills came amid renewed concerns over North Korean cruise missile threats after the country staged five rounds of cruise missile launches this year. The North claimed to have test-fired a new surface-to-sea missile off its east coast on Feb. 14.

North Korea also held live-fire artillery drills, involving units capable of striking Seoul, on March 7, its state media reported, in an apparent response to the annual South Korea-US Freedom Shield exercise that ended Thursday.

North Korea has one of the world's largest artillery forces, many of them positioned within range of the greater Seoul area, home to about half of South Korea's 51 million people. (Yonhap)