The U.S. State Department has approved on Tuesday the potential sale of $428 million in aircraft parts for Taiwan to help its air force, which is strained from repeatedly intercepting Chinese jets operating close to the island.

The Biden administration signed off on two new significant arms sales deals for selling spare aircraft parts to support Taiwan's fleet of F-16 fighters, C-130 transport planes and other U.S.-supplied weapons systems.

The package includes $330 million in standard replacement parts and $98 million in nonstandard equipment along with related accessories and logistics.

The sales were announced just weeks after President Joe Biden met his Chinese counterpart Xi Jinping for talks in Indonesia in which China’s increasingly aggressive behavior toward Taiwan was a major issue.

China regards Taiwan as a renegade province and has vowed to reunify the island with the mainland by force, if necessary. It has roundly condemned previous U.S. arms sales to Taiwan as violations of Washington's "One China" policy and is expected to react similarly to Tuesday's announcement.

But successive U.S. administrations of both parties have said ties with Taiwan are governed by the Taiwan Relations Act that allows the sale of military equipment to the island for its defense against potential threats from China.

"This proposed sale serves U.S. national, economic and security interests by supporting the recipient’s continuing efforts to maintain a credible defensive capability," the State Department said of the latest approvals.

"The proposed sale will help improve the security of the recipient and assist in maintaining political stability, military balance, and economic progress in the region," it said, adding that it would also "contribute to the sustainment of the recipient’s aerial fleet, enhancing its ability to meet current and future threats while providing defensive and transport capabilities critical to regional security."

Taiwan's Defense Ministry said on Wednesday the sale was expected to "take effect" within one month, and offered its thanks.

The United States is Taiwan's most important international arms supplier, despite the lack of formal diplomatic ties.

Taiwan's presidential office, noting this was the seventh arms sale approved by the Biden administration, said the latest approval would enhance Taiwan's combat power.

"Taiwan will continue to firmly demonstrate its determination and ability to defend itself and to firmly defend its sovereignty and protect national security," it said.