South Korea is joining a trilateral air drill involving the United States and Japan that is now in full swing in Alaska after the annual exercise was scaled down last year due to the COVID-19 pandemic, the US Indo-Pacific Command said Saturday.

The Red Flag exercise hosted by the US Pacific Air Forces runs from June 10-25 in Alaska to improve the three countries' interoperability and support security in the Indo-Pacific Region, the US command said.

"A series of commander-directed field training exercises provides joint offensive counter-air, interdiction, close air support, and large force employment training," the command said in a statement.

The Korean Air Force will be at Eielson Air Force Base and the Japan Self-Air Defense Force will be participating at Joint Base Elmendorf-Richardson, it noted.

It is the first time in three years that South Korea is participating in the multinational exercise, military officials here said earlier.

This year's exercise also marks the first trilateral military drill under the Joe Biden administration, which has called for closer security ties between Seoul and Tokyo to better deal with North Korea and China.

Last week, a North Korean propaganda outlet denounced Seoul's decision to send fighter jets and dozens of troops to join the US-led exercise, saying the South Korean military is "going through fire and water" for the US.

In response, Gen. Kenneth Wilsbach, commander of US Pacific Air Forces, said the Red Flag exercise is a routine training that is held "very frequently" and is aimed at enhancing their joint defense capability.

Launched in 1975, the Red Flag-Alaska drill is designed to integrate various forces and provide them with training opportunities in a realistic threat environment, according to the US military. (Yonhap)