WASHINGTON (AP) — Nearly half the Senate is urging President Barack Obama to authorize quickly a contentious sale of F-16 jet fighters to Taiwan.

Taiwan has been seeking the planes for five years. It says it needs the 66 F-16 C/Ds to maintain a credible defense and provide it leverage in negotiations with China, which regards the self-governing island as part of its territory.

A letter signed by 45 of the 100 senators and sent to Obama Thursday says that without new fighter aircraft and upgrades to Taiwan's existing fleet of F-16s, the island will be dangerously exposed to Chinese military threats.

The administration says it is still evaluating the request. Agreement to the multibillion dollar sale would anger China's communist-led government and would set back improved U.S.-China relations.