Leaders of Australia, India, Japan and the United States announced plans for new security initiatives in the Indian Ocean on Saturday, while outgoing U.S. President Joe Biden is hosting counterparts from the Quad grouping established out of shared concerns about China.

Biden welcomed Australian Prime Minister Anthony Albanese, Indian Prime Minister Narendra Modi and Japanese Prime Minister Fumio Kishida for a four-way meeting near his hometown of Wilmington, Delaware, to stress the importance…