US President Barack Obama administration says it has granted export licenses to US firms selling radar equipment to Taiwan in a move that could irk China.

Beijing angrily halted military and security contacts with Washington when the United States announced in January an arms package for Taiwan that included missiles, helicopters and equipment for Taiwan's F-16 fighter jets.

"We have notified congress as required under the Arms Export Control Act of proposed direct commercial sales between Taiwan and private US companies," State Department spokesman Philip Crowley told reporters on Tuesday.

Crowley said, under established rules, the foreign customer like Taiwan "enters into a direct relationship with a private US company," which must apply for an export license from the State Department.

"And the decision to approve these export licenses will allow the commercial export to Taiwan of defense services, technical data, and defense articles to support Taiwan's existing air defense radar system and upgrades to existing radars on Taiwan's indigenous defense fighter aircraft," Crowley said.

Congress, which receives the notification from the State Department usually as a formality, publishes the sales in the Federal Register.

Last week Taiwan's President Ma Ying-jeou renewed calls to Washington to sell the island an upgraded version of the F16 fighter, following a Pentagon report warning of China's growing military might.

Taiwan applied to the US government to buy 66 F-16 fighters in early 2007, but observers say Washington has held up the deal for fear of angering Beijing.

Mark Toner, a State Department spokesman, said Wednesday he knew nothing of any plans for the approval of F-16 sales to Taiwan.

China opposes any arms sales to Taiwan, which it considers a part of its territory awaiting reunification, by force if necessary, even though the two sides split in 1949 after a civil war and have been governed separately since.