Several F-35B stealth fighter jets conducted bombing practice on the Korean Peninsula earlier this week in support of joint training between South Korean and US marines, military authorities and sources said Saturday.

The US Marine Corps F-35 Lightning II aircraft are known to have returned to Japan after the Korea Marine Exercise Program as part of the allies' annual joint combined defense drills.

The US Forces Korea confirmed the sortie of the aircraft here, saying it reflects Washington's commitment to a robust alliance with Seoul.

"The deployment of the most advanced aircraft the USMC has in their inventory to Korea is yet another example of how dedicated the United States is to supporting the ROK-US Alliance," Gen. Vincent K. Brooks, who commands 28,000 American troops here, said in a statement. The ROK is the acronym for South Korea's official name, the Republic of Korea.

He added, "The training within the KMEP program helps ensure our readiness and is critical for our Alliance as we maintain security and stability on the Korean Peninsula."

The USFK did not provide details including the exact date of the F-35's flight over Korea and the number of deployed jets.

The KMEP was held from Monday through Thursday. A defense source said six to eight F-35s participated in the training. The jets conducted a simulation-based precision bombing drill in the Pilsung Shooting Range in the eastern province of Gangwon, added the source.

The USFK said, meanwhile, in addition to its short takeoff and vertical landing capability, the F-35B's unique combination of stealth, cutting-edge radar, sensor technology, and electronic warfare systems bring all of the access and lethality capabilities of a fifth-generation fighter.

The aircraft's training in South Korea was meant to "enhance and improve the interoperability of ROK and the US Marine Corps at the tactical level to build combined warfighting capabilities," the USFK said.

The latest bombing drill came amid the region's rising tension over North Korea's continued provocations. Successive media reports say another nuclear weapons test appears to be imminent in the North.

The US deployed 10 F-35Bs to its Marine Corps Air Station Iwakuni in Japan's Yamaguchi Prefecture in January, with six more scheduled to be positioned there within this year.

US soldiers and equipment at the base will be among the first to be deployed to Korea in case of a contingency on the peninsula. (Yonhap)