By CHRISTOPHER BODEEN, Associated Press

China expressed its opposition Monday to a reported deal between the United States and Taiwan to upgrade Taiwan's existing fleet of F-16 fighter jets, even though the U.S. apparently rejected the island's bid for a more advanced version of the plane.

Although the Obama administration has yet to issue a formal notification of the F-16 deals, two congressional aides privy to the results of a Capitol Hill briefing on the issue told The Associated Press it nixed the Taiwanese request for 66 relatively advanced F-16 C/Ds, while agreeing to upgrade the island's existing fleet of F-16 A/Bs.

The fighter jets have been a dominant issue in the uneasy triangular relationship between Taipei, Washington and Beijing throughout the 3 1/2 year presidency of Taiwan's Ma Ying-jeou. Despite reducing tensions across the 100-mile (160-kilometer) -wide Taiwan Strait to their lowest level since China and Taiwan split amid civil war in 1949, Ma has pressed for the new warplanes, saying Taipei needs them to continue negotiating with Beijing from a position of strength.

That has put the U.S. in a difficult position, forcing it to try to balance its congressionally mandated responsibility to provide Taiwan with weapons to defend itself against a possible Chinese attack with a desire to keep its increasingly important relations with Beijing on an even keel.

China reacts angrily to any foreign military sales to Taiwan, because it regards the democratic island of 23 million people as part of its territory. It 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.

Speaking at daily news briefing in Beijing on Monday, Chinese Foreign Ministry spokesman Hong Lei said China's opposition to American arms sales to Taiwan has been "consistent and clear."

Without indicating what action China might take because of the F-16 upgrade, Hong said the United States should "refrain from selling arms to Taiwan so as to avoid impairing bilateral relations as well as the peaceful development of cross-strait relations."

Hong's comments were relatively muted in comparison to the ferocity of China's response when last year's arms package was announced. While China's powerful military and nationalistic public opinion have called for retaliation — including against the U.S. companies involved — Beijing has so far relied on diplomatic channels to register its unhappiness.