Three US carrier strike groups are currently operating off the Korean coast with ships of Japan’s Maritime Self-Defense Force, according to USNI News, which posted a video clip of the joint exercises scheduled during US President Donald Trump’s visit to Asia.

The video shows the huge US carriers Ronald Reagan, Nimitz and Theodore Roosevelt sailing abreast of each other in tight formation escorted by a covering screen of more than a dozen warships.

Japan’s Asahi Shimbun is reporting that the Japanese naval vessels include three destroyers: the Inazuma, Makinami and Ise.

The joint drill follows stern words from Trump and Japanese Prime Minister Shinzo Abe last week that the time has come to apply “maximum pressure” on North Korea for its continuing nuclear provocations.

Korean Navy absent

Asahi quotes a Japanese government source as saying that there was “an attempt” to have South Korean Navy ships join the exercise in the Sea of Japan. But the newspaper reported “an agreement on timing could not be reached to allow (South Korea) to participate in a trilateral training exercise.”

China and South Korea recently agreed to resolve their dispute over Seoul’s earlier decision to deploy a US THAAD antimissile system in return for a dropping of retaliatory Chinese sanctions. Some analysts believe that the understanding with Beijing involves South Korea pulling back from openly backing a ROK-US-Japan trilateral military alliance. As part of this, they say South Korea has agreed to at least symbolically distance itself from a US-led strategy of containing China.