(Reuters) -China vowed “resolute countermeasures” on Sunday to a recently approved U.S. arms sale to Taiwan, and complained to the U.S. for arranging for the democratically governed island’s president to transit through U.S. territory.

The U.S. State Department approved the potential sale, worth an estimated $385 million, of spare parts and support for F-16 jets and radars to Taiwan, the Pentagon said on Friday.

The sale was announced hours before Taiwan’s President Lai Ching-te left on a visit to Taipei’s three diplomatic allies in the Pacific, with stops in Hawaii and the U.S. territory of Guam.

The sale sends “a wrong signal” to Taiwan independence forces and undermines U.S.-China relations, China’s foreign ministry said in a statement.

The ministry said in a separate statement that it firmly opposes any official exchanges between the U.S. and Taiwan and “strongly condemns” the U.S. for arranging the transit.

China, which views democratically governed Taiwan as its own territory and the most important issue in its relations with Washington, strongly dislikes Lai, calling him a “separatist”.

The United States is bound by law to provide Taiwan with the means to defend itself despite the lack of formal diplomatic ties between Washington and Taipei, to the constant anger of Beijing.

Taiwan rejects China’s claims of sovereignty.

(Reporting by David Kirton in Shenzhen; Editing by William Mallard)