TOKYO—An American aircraft carrier heading toward the Korean Peninsula began joint exercises Sunday with Japanese naval ships in the Philippine Sea.

Two Japanese destroyers joined the USS Carl Vinson and two other U.S. warships as they continued their journey north in the western Pacific Ocean, the U.S. Navy said in a statement.

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The Vinson had cancelled a scheduled visit to Australia to divert toward North Korea in a show of force, though it still conducted a curtailed training exercise with Australia before doing so. Tensions are elevated on the Korean Peninsula, with the Trump administration saying that all options are on the table, and indications that North Korea may be preparing to test a nuclear weapon or long-range missile.

Two Japan Maritime Self-Defence Force destroyers left Sasebo port in southern Japan on Friday to join the Vinson strike group. The U.S. group also includes a guided-missile cruiser and a guided-missile destroyer.

The Navy called the exercise “routine” and said it is designed to improve combined maritime response and defence capabilities, as well as joint manoeuvring proficiency.

The Vinson group has conducted three previous bilateral exercises with the Japanese navy since leaving San Diego on Jan. 5 for a western Pacific deployment. The most recent one was in March.

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