"The wrongdoing by the U.S. side will inevitably undermine bilateral relations as well as exchanges and cooperation in military and security areas," Vice Foreign Minister Zhang Zhijun said in a statement Thursday, after summoning U.S. Ambassador Gary Locke to Beijing to personally deliver the protest and warn of repercussions, the official Xinhua News Agency reported.
Zhang told Locke the proposed sale was a "wrong decision" that the Obama administration should "immediately cancel" before it produces "serious harm," Xinhua said.
China considers the proposed deal a severe interference in China's internal affairs that undermines China's national security, Zhang said.
Beijing claims Taiwan, a sovereign state, as its territory and has repeatedly warned Washington against selling weapons to the democratically ruled island.
A senior Obama administration official told reporters Wednesday the upgraded Lockheed Martin Corp. F-16 dogfighters would "provide a substantial increase in the survivability, the reliability and the combat capabilities and effectiveness" of Taiwan's fleet of 145 F-16s.
"We believe that our arms sales to Taiwan contribute to the maintenance of peace and stability across the Taiwan Strait," he said, referring to the 99-mile wide channel that separates China from Taiwan.
The F-16s, which Washington sold to Taiwan in 1992 during the George H.W. Bush administration, would be upgraded with new radar and an array of weapons -- including targeting systems, air-to-air missiles and joint direct attack munition kits that convert unguided "dumb" bombs into all-weather "smart" bombs.
Washington proposed to train Taiwanese fighter pilots in the United States, said the Defense Security Cooperation Agency, which oversees foreign military sales.
The Pentagon formally notified Congress of the package Wednesday, ending prolonged speculation over the extent to which Washington would help modernize the island republic's air force.
U.S. lawmakers expressed concern the upgrade package wouldn't be enough to modernize Taiwan's air defenses amid fears the military balance across the strait favored China.
Sen. John Cornyn, R-Texas, called the proposed sale a "capitulation" to Beijing.
"Taiwan must have the tools to defend itself against potential Chinese aggression," he said in a statement.
Rep. Kay Granger, R-Texas, introduced legislation in the House requiring the Obama administration to sell 66 new F-16C/D multi-role jet fighters to Taiwan, matching legislation Cornyn and Sen. Robert Menendez, D-N.J., previously introduced in the Senate.
The single-seat F-16Cs and the dual-seat F-16Ds have improved cockpit avionics and radar, along with beyond-visual-range air-to-air missiles that can hit targets more than 20 nautical miles away.
The United States is required to provide Taiwan with arms to defend itself under the Taiwan Relations Act, passed by Congress in 1979 after Washington and Beijing established full diplomatic ties.