The Obama administration has decided to upgrade Taiwan's existing fleet of F-16 fighter jets but not sell it the new planes it also wants, congressional staff said.
The administration gave a briefing on Capitol Hill on its decision Friday, but has yet to issue a formal notification of the intended deal. An announcement is expected by the end of this month.
Two congressional aides confirmed the decision to The Associated Press on condition of anonymity as they were not authorized to make it public.
The decision represents a compromise aimed at improving Taiwan's ability to defend itself, while assuaging China's concern over the arms sales. However, Beijing is still expected to react angrily. It regards the self-governing island as part of its territory.
There will also be criticism from Republicans and some Democrats in Congress who have strongly backed the sales of 66 F-16 C/D fighters that Taiwan wants, in addition to the upgrades of the 145 F-16 A/Bs that the U.S. sold it in the 1990s.
There were no immediate details on the package of upgrades the U.S. is providing for the A/Bs. But even if it includes sophisticated radar, avionics and missile systems, Taiwan's air force will still lag far behind its Chinese counterpart, which is equipped with state-of-the-art jet fighters.
A Pentagon report issued last year painted a grim picture of Taiwan's air defense capabilities, saying many of the island's 400 combat aircraft would not be available to help withstand an attack from the mainland.
Wang Kao-cheng, a military expert at Taipei's Tamkang University, said Taiwan's air defenses could get some lift from the upgrade, but the island is still at a profound disadvantage with Beijing in the number of third-generation warplanes it has at its disposal.
"Taiwan has fallen behind in air superiority as of now, not to mention the fact that China is developing the fourth-generation stealth fighters, which could be very powerful," Wang said. "The upgrade program will not fill the vacuum left over by the absence of the C/Ds."
On Friday, Republican Sen. John Cornyn of Texas, where the Lockheed Martin plant that would build the F-16s is located, said the decision would be a slap in the face to strong ally Taiwan.
Howard Berman, the ranking Democrat on the House of Representatives Foreign Affairs Committee, called it a "half-measure." He said Taiwan needed more advanced fighter aircraft to defend itself against increasing Chinese military threat.
China and Taiwan split amid civil war in 1949. While Taiwan's relations with the mainland have greatly improved in the past three years and tensions across the Taiwan Strait are their lowest in six decades, China's military buildup has carried on apace.
The United States is legally obligated to sell weapons to Taiwan for its self-defense. The last major arms sale announced in early 2010 prompted China to cut military ties with the U.S. for several months.
Taiwan's Defense Ministry said it had no immediate comment on the U.S. F-16 decision.
China's Defense Ministry and Ministry of Foreign Affairs did not respond immediately to faxes asking for comment, and calls to the Taiwan Affairs Office rang unanswered Monday.
The official China Daily newspaper had a front-page article Monday warning that an arms sale would "spark strong reaction."
It quoted Tao Wenzhao, a senior researcher at Tsinghua University in Beijing, as saying "the (arms sale) hurts China's core interests. And to keep on doing the wrong thing for 30 years just doesn't make it right."
China temporarily suspended military exchanges with the U.S. last year after the Obama administration notified Congress it was making $6.4 billion in weapons available to Taiwan, including missiles, Black Hawk helicopters, information distribution systems and two Osprey Class Mine Hunting Ships.
Associated Press writers Scott McDonald in Beijing, and Peter Enav and Annie Huang in Taipei contributed to this report.