March 22 (UPI) -- The United States deployed a supersonic bomber during joint exercises on the Korean peninsula on Wednesday, South Korean military sources said.
Two B-1B Lancers, long-range, multi-mission conventional bombers nicknamed "The Bone," were deployed to warn North Korea, South Korean news service News 1 reported.
Two B-1B bombers were also deployed to Korea on March 15, Yonhap reported.
News 1's source said the bombers from Guam arrived on the peninsula on Wednesday during the joint annual exercises Foal Eagle.
At Kunsan Air Base, the aircraft carried simulated bombing missions, the report said.
South Korea air fleets, including the F-15K and KF-16 fighter squadrons, flew in formation with the B-1B Lancers after they entered Korea's air defense identification zone.
The bombers also flew with Japan's air self-defense force's F-15J fighters in Japan's air defense identification zone, or JADIZ.
A South Korean defense ministry official who spoke to News 1 on the condition of anonymity said, "Through the training, the South Korea and U.S. air forces demonstrated a capacity for strong deterrence on one hand, and on the other improved interoperability of U.S.-South Korea fighting power."
The official said there is "great significance" in the deployment of U.S. strategic assets to the peninsula.
Last week North Korea condemned U.S. deployment of the nuclear-capable bomber, and accused the United States of "deepening the threat of nuclear weapons."
The United States has signaled interest in placing more pressure on Pyongyang to give up its own weapons of mass destruction.
On Tuesday House Foreign Affairs Committee Chairman Rep. Ed Royce, R-Calif., introduced a bill that can strengthen U.S. sanctions against North Korea to curb weapons development and "crack down on the Kim regime."
"North Korea's nuclear arsenal poses a growing and urgent threat to the United States. Soon, many believe the Kim Jong Un regime will be able to target all 50 states and our Asian allies with a nuclear warhead," Royce said.