The leaders of the United States, Japan and the Philippines agreed Thursday to step up their defense and economic cooperation, in a move aimed at pushing against China’s ambitions in the Indo-Pacific region. U.S. President Joe Biden, Japanese Prime Minister Fumio Kishida and Philippine President Ferdinand Marcos Jr. expressed “serious concerns” about China’s “dangerous and aggressive” actions in the South China Sea in a statement released after the first-ever summit of the three countries, held in Washington.