There is a possibility of the MSDF conducting drills with the two flat tops, the sources said, adding that the Japanese and U.S. vessels are expected to carry out tactical exercises to confirm their formations and drills to ensure their smooth communications.
The Vinson, a nuclear-powered flattop based in San Diego, arrived in the East Sea in late April as a warning to North Korea over its continued provocations.
The U.S. sent the second of the two aircraft carriers to the Korean peninsula this week, in response to the increasingly frequent missile tests carries out by North Korea, including a test launch of a SCUD missile on Monday that penetrated Japan's "Exclusive Economic Zone" in the Sea of Japan. The United States also could launch airstrikes at any time by unleashing about 150 F-16 jets stationed in South Korea and Misawa Air Base in Aomori Prefecture; F/A-18 strike fighters on its aircraft carriers; and strategic bombers based in Guam. Earlier this week, North Korean leader Kim Jong Un promised to send the US a bigger "gift package".
All together, 10 US warships sailed together with two ships from the Japanese Maritime Self Defense Force in a photo dated June 1 from the Sea of Japan.
North Korea can already strike anywhere in Japan with missiles, raising concern in Tokyo that it could eventually be threatened by a North Korean nuclear strike.
It comes amid heightened tensions on the Korean peninsula over fears the North is about to conduct a sixth nuclear test as it tries to develop an intercontinental ballistic missile capable of hitting the mainland US.
Instead, Helvey said that despite the fact that such joint exercises had not been carried out in two decades, this week's operations were simply routine and designed only to increase the military readiness of both countries. United States and Japanese leaders had agreed 26 May to increase tangible pressure on North Korea. North Korea also possesses numerous submarines, meaning an unintentional maritime clash is not out of the question.
"This unique capability is one of many ways the U.S. Navy promotes security, stability and prosperity throughout the Indo-Asia-Pacific", he added.
"The U.S. special forces unit involved in such a raid would suffer significant losses", a Japanese government source said.