South Korea's Air Force on Monday kicked off a biannual aerial combat exercise, involving its radar-evading F-35A fighters and dozens of other warplanes, in order to ensure a "firm" readiness posture, the armed service said.

The five-day Soaring Eagle exercise began amid lingering tensions caused by North Korea's continued ballistic missile launches and speculation that it has completed preparations for what would be its seventh nuclear test.

The training got under way at the 29th Tactical Fighter Weapons Group in Cheongju, 137 kilometers south of Seoul. It mobilized some 200 personnel and about 70 warplanes, including F-35As, F-15Ks, KF-16s, F-4Es, F-5s, E-737 early warning and control aircraft and CN-235 transport planes, according to the Air Force.

"This exercise is aimed at ensuring we are equipped with capabilities to rapidly respond to enemy provocations, and with the best operational capabilities through the verification of our strike capabilities against high-threat targets," Col. Lee Chul-woo, head of the air force unit, said.

Under a scenario of large-scale enemy infiltrations, participants practiced operations to detect, identify and intercept hostile air targets from a long distance, and conducted massive formation maneuvers to strike key enemy forces and origins of possible provocations.

The practice also involved the application of the Air Combat Maneuvering Instrumentation system that provides real-time information required for pilots to accurately understand battle situations and thus improve their combat capabilities.

Launched in 2008, the Air Force has conducted the Soaring Eagle twice a year. (Yonhap)