Obama sought broader relations with China on his maiden visit this week and is widely seen as reluctant to act soon on Taiwan's request to buy F-16 fighter-jets, which the island says it needs to modernize its aging fleet.

Taiwan's backers from both major parties in the House of Representatives sponsored a bill that would force the Obama administration to explain to Congress its plans on defense cooperation with Taiwan.

If approved, the bill would require Secretary of State Hillary Clinton and Defense Secretary Robert Gates to provide "detailed briefings" to Congress on the issue within 90 days.

The measure was led by Congresswoman Ileana Ros-Lehtinen, the top Republican on the House Foreign Affairs Committee. She was joined by four Republicans and three lawmakers from Obama's Democratic Party.

Taiwan is unlikely to be an urgent priority for Congress, which enters the holiday season wrapped up in negotiations on Obama's key domestic priorities such as extending health care coverage and battling climate change.

But one congressional aide said that the bill was a sign that lawmakers were frustrated on Taiwan. There is a growing concern that the foreign military sales process with respect to Taiwan is becoming dysfunctional due to indecisiveness, which is in effect paralyzing the process," the aide said on condition of anonymity.

A Republican congressman, Joe Barton, introduced a separate bill that would call on the United States to make a decision on arms sales "based solely" on Taiwan's defense needs.

Beijing considers Taiwan, where nationalists fled in 1949 after losing the mainland's civil war to the communists, to be a province awaiting reunification, by force if necessary. The United States in 1979 switched recognition from Taipei to Beijing. Obama reiterated on his visit that the United States believed there was only one China.

Congress, long Washington's hotbed of support for Taiwan, responded to the switch 30 years ago by approving the Taiwan Relations Act that requires the United States to provide the island with weapons of a defensive nature.

China angrily denounces such arms sales. It cut off military exchanges with the United States for months after the George W. Bush administration in October 2008 unveiled a 6.5-billion-dollar arms package for Taiwan, which included Patriot missile defenses and Apache attack helicopters but not F-16s.