The State Department said it informed Congress of the $500 million sale of F-16 Infrared Search and Track systems and related equipment to help Taiwan "maintain a credible defensive capability."

The sale will help Taiwan "meet current and future threats by contributing to the recipient's abilities to defend its airspace, provide regional security and increase interoperability with the United States through its F-16 program."

The new system, built by Lockheed Martin, improves fighter jets' ability to detect airborne threats, increasing the chances of F-16s' survival during combat.

China claims Taiwan, a self-ruling democracy, and has stepped up saber-rattling over the past year in response to Taiwanese leaders' interactions with the United States.

It staged its latest drills around the island on Saturday, with Taiwan detecting 45 warplanes entering its air defense zone.

The United States only recognizes Beijing but for more than four decades has sold weapons to Taiwan to ensure its self-defense.

US lawmakers, seeing a rising threat by China, have recently been moving to go further and to aid Taiwan directly as the United States does to Ukraine.