TAIPEI, Taiwan — The United States has tentatively approved the sale of $2 billion in military hardware to Taiwan, demonstrating support for its unofficial ally in a move likely to exacerbate deteriorating ties between Washington and Beijing.

The Defense Security Cooperation Agency, part of the United States Defense Department, notified Congress of two proposed arms sales on Monday. The first notification included 108 M1A2T Abrams tanks, as well as Hercules armored vehicles and heavy equipment transporters. The second included more than $220 million in Stinger antiaircraft missiles.

The tentative approvals come as relations between the United States and China are already being tested by a trade war and the decoupling of technology supply chains. The armaments would provide Taiwan with greater deterrence capabilities against the growing military threat from China, experts said.