On an epic trip, Secretary of State Antony J. Blinken tried to reassure Asian leaders about American commitments. But China remains the enduring backyard behemoth.

Secretary of State Antony J. Blinken and Defense Secretary Lloyd J. Austin III warned Beijing against engaging in hostilities with U.S. allies in the South and East China Seas.

The two governments said the moves were a response to growing aggression by China, whose rapid military buildup has many leaders worried.

The U.S. secretary of state pressed China’s top foreign policy official on Beijing’s support for Russia’s efforts to rebuild its military industries during the Ukraine war.

Asian officials will press Secretary of State Antony J. Blinken about the former president and about Kamala Harris as he visits the region.

The Biden administration is trying to get foreign companies to invest in chip-making in the United States and more countries to set up factories to do final assembly and packaging.