SEOUL (Kyodo) -- Japan, the United States and South Korea held joint air drills with a U.S. B-1B strategic bomber on Wednesday, the South Korean defense ministry said, following North Korea's recent firings of missiles including what Pyongyang has said was a hypersonic missile.

Japanese and South Korean fighter jets joined the trilateral exercise which took place over the high seas near the Korean Peninsula, according to the ministry.

The ministry said it will "contain the threat posed by North Korea through expanding drills by the three nations."

North Korea launched a ballistic missile toward the Sea of Japan on Jan. 6, with its official Korean Central News Agency saying the following day that a new type of intermediate-range hypersonic missile had been fired and successfully flew 1,500 kilometers to a simulated target at sea.

On Tuesday, North Korea fired several short-range ballistic missiles, which traveled around 250 km before falling into the Sea of Japan, according to the South Korean military.