Leaders of Australia, India, Japan and the United States will announce plans for new security initiatives in the Indian Ocean on Saturday, when outgoing U.S. President Joe Biden hosts counterparts from the Quad grouping established due to shared concerns about China.

A “hot mic” incident, in which Biden told the other leaders that Beijing was “aggressive” and “testing us,” underscored the real thrust of the anti-China summit.

"It will survive way beyond November," Mr. Biden declared of the Quad as the leaders gathered at the Archmere Academy, his high school alma mater.