Three nuclear-capable B-2 Spirit bombers have been dispatched to the Asia-Pacific with the largest-ever war games with South Korea — involving participation by Hawaii forces — prompting threats of nuclear retaliation from the North.

“Strategic bomber deployments ensure our ability to project power at a time and place of our choosing and develop strong interoperability with our regional allies and partners,” Gen. Lori J. Robinson, commander of Pacific Air Forces headquartered in Hawaii, said in a release. “Recent events demonstrate the continued need to provide consistent and credible air power throughout the Indo-Asia-Pacific region. Our ability to demonstrate credible combat power while training and interoperating with our network of like-minded partner nations is vitally important.”

North Korea tested in January what it said was a hydrogen bomb, and today fired two short-range ballistic missiles as exercises continue with the United States and other nations, raising tensions even higher with the hermit kingdom.

Approximately 17,000 U.S. forces are participating with South Korea in the annual Key Resolve and Foal Eagle exercises, U.S. Forces Korea said. The troops are operating alongside more than 300,000 South Korean forces during the war games, which are being conducted “on an unprecedented scale,” according to the Korea Times.

That includes involvement by the B-2 bombers, the Hawaii-based Virginia-class submarine USS North Carolina, and USS John C. Stennis carrier strike group, the newspaper reported.

About 7,000 sailors make up the carrier strike group, which includes the guided missile destroyer USS Chung-Hoon out of Pearl Harbor. The strike group crossed the international date line into the U.S. 7th Fleet area of operations on Feb. 4.

Roughly 300 Hawaii Marines from 1st Battalion, 3rd Marines, are in Pohang, South Korea, meanwhile, in support of exercise Ssang Yong 16, said Marine Corps spokesman Capt. Tim Irish.

The exercise is meant to increase interoperability with the Republic of Korea Navy and Marine Corps, Australian Army, and New Zealand Defense Forces while practicing a forcible entry operation, Irish said.

Marines and sailors of the 3rd Marine Expeditionary Brigade, Expeditionary Strike Group 7 and Task Force 76 are participating in the drills with 5,000 South Korean Marines and Navy personnel, along with forces from Australia and New Zealand, the Korea Times said.

North Korea’s National Defense Commission said on Monday that the United States and South Korea assert that the war games constitute “crucial pressure” following a United Nations sanctions resolution that “was forged unreasonably picking a quarrel with the country’s self-defense first H-bomb test and the legitimate launch of Kwangmyongsong 4 Earth observation satellite.”

Many observers believe the February satellite launch was a ballistic missile test.

“The gravity of the situation doubles” with the testing of the United States’ OPLAN (Operation Plan) 5015 to carry out what North Korea dubbed a “beheading operation” aimed at neutralizing the North’s supreme leadership and system overthrow.

OPLAN 5015 calls for a prompt response to a North Korean attack with a preventive strike on the North’s core military facilities and weapons, as well as top leaders, the website GlobalSecurity.org reported.

“Strike means” have been deployed for major targets in South Korea and “powerful nuclear strike means levelling at the U.S. military bases for aggression in the Asia-Pacific and its mainland are on constant standby for launching attack,” the North said.