WASHINGTON (AP) — The Trump administration has informed Congress it plans to sell F-16 fighters worth $8 billion to Taiwan in a move that will inflame already high tensions with China.

Two U.S. officials and a congressional aide say the administration informally notified lawmakers of the proposed sale late on Thursday. They were not authorized to discuss the matter publicly and spoke on condition of anonymity.

The F-16 deal is highly controversial because China fiercely opposes all arms sales to Taiwan, which it regards as a renegade province, but has specifically objected to advanced fighter jets. The notification also comes as U.S. trade talks with China are stalled and amid unrest in Hong Kong that many fear could prompt Beijing to move militarily against the former British colony.

The State Department, which would ultimately authorize the sale, declined to comment, but Republican Sen. Ted Cruz of Texas, a member of the Senate Foreign Relations Committee and staunch Taiwan supporter, welcomed the notification.

"Today the administration took a critical step toward bolstering the national security of the United States and our longstanding ally Taiwan with the sale of F-16s," he said in a statement. "With China building up its military to threaten us and our allies, and the People's Liberation Army aiming thousands of missiles at Taiwan and deploying fighter aircrafts along the Taiwan Strait, now more than ever it is critical that Taiwan has the support needed to defend itself."

The informal notification starts a period of consultations with Congress and a formal announcement of the sale could be made as early as next month unless lawmakers object. Cruz said he would work his colleagues to ensure the sale proceeds smoothly.

Just this week, America's top representative in Taiwan said Washington expects the island to continue increasing its defense spending as Chinese security threats to the U.S. ally continue to grow. W. Brent Christensen said the U.S. had "not only observed Taiwan's enthusiasm to pursue necessary platforms to ensure its self-defense, but also its evolving tenacity to develop its own indigenous defense industry."

That was a nod to President Tsai Ing-wen's drive to develop domestic training jets, submarines and other weapons technology, supplementing arms bought from the U.S.

Christensen is the director of the American Institute in Taiwan, which has served as the de facto U.S. Embassy in Taiwan since formal diplomatic relations were cut in 1979.

While China and Taiwan split during a civil war in 1949, Beijing still considers Taiwan Chinese territory and has increased its threats to annex the self-governing democracy by force if necessary.

Despite the lack of formal diplomatic ties, U.S. law requires Washington to ensure Taiwan has the means to defend itself.

Since 2008, U.S. administrations have notified Congress of more than $24 billion in foreign military sales to Taiwan, including in the past two months the sale of 108 M1A2 Abrams tanks and 250 Stinger missiles, valued at $2.2 billion, Christensen said. The Trump administration alone has notified Congress of $4.4 billion in arms sales to Taiwan.

China has responded furiously to all such sales and recently announced it would impose sanctions on any U.S. enterprises involved in such deals, saying they undermine China's sovereignty and national security.

Tsai has adamantly rejected Chinese pressure to reunite Taiwan and China under the "one-country, two-systems" framework that governs Hong Kong. She and many Taiwanese have said that the people of the island stand with the young people of Hong Kong who are fighting for democratic freedoms in ongoing protests.

Beijing has cut contacts with Tsai's government over Tsai's refusal to endorse its claim that Taiwan is a part of China and sought to increase Taiwan's international isolation by reducing its number of diplomatic allies to just 17.China has also stepped up efforts at military intimidation, holding military exercises across the Taiwan Strait and circling the island with bombers and fighters in what are officially termed training missions.