The United States on Wednesday sent two armed strategic bombers to South Korea, the US Forces Korea said, in the latest move to demonstrate Washington's security commitment to its Asian ally and warn against additional North Korean provocations.

One of the two B-1B Lancer bombers landed at Osan Air Base. The other flew over the base in Pyeongtaek, 70 kilometers south of Seoul, and returned to US Andersen Air Force Base on Guam, the USFK said.

The flyby comes only a week after a pair of B-1B Lancers flew over South Korea days after the North conducted its fifth nuclear test. The move is aimed at reaffirming Washington's commitment to providing Seoul with extended deterrence amid Pyongyang's growing missile and nuclear threats.

"The bond between the United States and the Republic of Korea is ironclad and the strength of that commitment will not be shaken by North Korea's aggressive behavior," 7th Air Force Commander Lieutenant Gen. Thomas W. Bergeson said in a statement released by the USFK.

"What we are showing today is just one tool we have to choose from a wide array of options. The alliance grows stronger every day and we remain prepared to defend and to preserve the security of the Korean Peninsula and the region."

The Combined Air Forces of the two allies maintain close information sharing and a robust joint operational capability, said Lt. Gen. Lee Wang-keun, South Korea's Air Force Operations Commander.

"Should the enemy provoke us once again, the South Korea-US combined forces will respond and eliminate their will and capability to fight," he warned.

It remains uncertain how long the Lancer will stay in Korea and whether the strategic bomber will be open to the public. The 7th Air Force of the US is scheduled to hold its "Air Power Day" event this weekend and open its base to the public.

The B-1B, capable of reaching the peninsula from Guam in just two hours, is one of the US military’s three major multi-role and long-range bombers along with the B-52 Stratofortress and B-2 Spirit. 

The Lancer, which has the ability to fly very low and faster while carrying a large payload, represents a major upgrade in US long-range bombing capability over the B-52.

There is a possibility that the US will send B-52s and B-2s to Korea as well. 

Pyongyang has continued such provocative acts as nuclear tests and long-range rocket launches despite a wide range of UN-led sanctions.

On Jan. 10, four days after the North's fourth nuclear test, the US flew a B-52 bomber over South Korea. The B-52 can carry nuclear missiles and "bunker buster" bombs that are capable of destroying the North's underground facilities. (Yonhap)