SEOUL - Republic of Korea and the United States launched their largest-ever joint air exercise on Friday to beef up their combined strategic capability amid the escalating tensions over the peninsula.

The "Max Thunder" exercise, which will last from April 11 to 25 over the entire airspace of ROK, involves 103 aircraft and 1,400 service personnel, according to the ROK's air force.

ROK air force has sent some 50 fighter jets such as F- 15k, KF-16 and E-737 along with around 50 US warplanes including F-15, F-16s, FA-18, EA-18 and AWACS, or an early warning aircraft.

The air exercise, which is held twice a year through realistic trainings to simulate air battles between two sides, was considered to be the largest one of this kind in numerical terms, Seoul's air force said.

An official from ROK's air force command said the joint drill was to enhance the army's readiness amid the rising tensions over the Peninsular.

The largest-ever air exercise came after three drones suspected of coming from the Democratic People's Republic of Korea(DPRK) were discovered in the eastern and western frontline areas in recent weeks.

Seoul and Pyongyang also exchanged artillery fires into the sea across the western maritime border on March 31.

ROK and the United States conducted another live-fire exercise in Pocheon, a city near the border with the DPRK on Friday afternoon, as part of the allies' annual joint drill "Foal Eagle", which lasts from Feb. 24 to April 18.

Around 350 ROS's and US soldiers, Seoul's K-1 battle tanks, US Army's OH-58D Kiowa Warrior helicopters and others joined in the drill.