The first such deployment of three U.S. carriers since 2007 "is making it impossible to predict when nuclear war breaks out due to the United States nuclear war equipment" taking up a "strike posture", he wrote. This is the first time that three carrier strike groups have operated together in the Western Pacific since exercises Valiant Shield 2006 and 2007 off the coast of Guam.
The joint drill comes just days after Prime Minister Shinzo Abe and U.S. President Donald Trump agreed that now is the time to apply "maximum pressure" on North Korea for its continuing military provocations.
Three U.S. Navy nuclear-powered Nimitz-class aircraft carriers-the USS Ronald Reagan, USS Nimitz, USS Theodore Roosevelt-kicked off a four-day naval drill in the Western Pacific on November 11.
The exercise involves three USA aircraft carrier groups, making it the largest show of force in a decade.
"The participating forces of the two nations plan to enhance combined operation capability and interoperability through aircraft carrier escort operation, aviation operation and aerial firing", said the JCS.
The exercise involves the Roosevelt, USS Ronald Reagan and USS Nimitz and includes air defense drills, sea surveillance, replenishments at sea, defensive air combat training, close-in coordinated maneuvers and other training, Navy officials said.
"#Japan says it'll send one of its big helicopter carriers to join three United States aircraft carriers for exercises in waters close to #Korea peninsula", VOA Correspondent Steve Herman tweeted.
"Multiple carrier strike force operations are very complex, and this exercise in the Western Pacific is a strong testament to the U.S. Pacific Fleet's unique ability and ironclad commitment to the continued security and stability of the region".
Admiral Scott Swift, Commander of the U.S. Pacific Fleet, speaks at a news conference at Changi Naval Base in Singapore August 22, 2017.