The U.S. State Department has approved a possible $500 million sale to Taiwan of infrared search and track systems for F-16 fighter jets, as well as other equipment, the Pentagon said on Wednesday.

"The proposed sale of this equipment and support will not alter the basic military balance in the region," it said in a statement. The move could irritate Beijing, which repeatedly demanded the United States - Taiwan's most important arms supplier - halt the sale of weapons to the island.

The Pentagon said the principal contractor would be Lockheed Martin Corp, which makes the F-16.

Taiwan's military spending will rise by 3.5% year-on-year to hit a fresh record high in 2024, President Tsai Ing-wen said on Monday, pledging to improve defenses amid a growing threat from China, which views Taiwan as its own territory.

The $500 million is the maximum potential value of the contract and the actual dollar value will be lower, the Pentagon said. The United States unveiled a Taiwan weapons aid package worth up to $345 million late last month.

Despite approval by the State Department, the notification does not indicate that a contract has been signed or that negotiations have concluded.