The South Korean and U.S. air forces began a large-scale, regular joint maneuver Monday to sharpen their ability to work together in simulated war situations, officials said, amid growing concerns that North Korea may conduct a third nuclear test.

About 60 warplanes from the allies, including a U.S. aerial refueling aircraft, are taking part in the annual Max Thunder exercise, which will run through May 18, Seoul's military officials said.

Hundreds of pilots were mobilized for the drill over the southwestern airspace of the Korean Peninsula, Air Force officials said.

Training missions include simulating air battles with four or eight jets, air refueling involving a KC-135 Stratotanker aerial refueling aircraft and neutralizing an enemy's air defense system in case of an all-out war, officials said.

"The drill will display our readiness and joint air firepower with the U.S. that can immediately retaliate in case of an emergency on the Korean Peninsula," an Air Force official said.

There is growing speculation that North Korea may stage another provocation, including a third nuclear test, following the failed launch of a long-range rocket last month.

North Korea defiantly launched a long-range rocket on April 13 despite international warnings, but it broke into pieces right after takeoff.

Since late last month, the North has warned of a "special action" against the South, saying it will "soon" turn the South Korean government and other specific targets into "ashes."

About 28,500 U.S. troops are stationed in South Korea, a legacy of the 1950-53 Korean War. (Yonhap)