China yesterday demanded the U.S. cancel a $330 million sale of military equipment to Taiwan, warning of "severe damage" to bilateral relations and mutual cooperation if Washington fails to comply.

Foreign ministry spokesman Geng Shuang told reporters at a regular briefing that the sale violated international law and the "basic norms governing international relations."

"We urge the U.S. side to ... immediately cancel this arms sale plan, and stop military contact with Taiwan so as to avoid severe damage to China-U.S. ties, peace and stability in the Taiwan Strait and bilateral cooperation in major fields," Geng said, as reported by The Associated Press.Washington remains Taipei's most powerful unofficial ally and its main arms supplier despite switching diplomatic recognition to Beijing in 1979. The Trump administration said Monday that it had approved the sale of spare parts and related support for Taiwan's U.S.-made F-16 fighters and other military aircraft.

The U.S. said the sale will improve Taiwan's ability to defend itself without altering the basic military balance in Asia, where Washington and Beijing are increasingly competing for dominance. China as a principle opposes all U.S. military sales to Taiwan, which split with the mainland in 1949 but which Beijing continues to claim as part of its territory and threatens to invade to bring under its control.Congress has 30 days to raise objections to the sale, though this is unlikely given the State Department has determined Taiwan continues to be "an important force for political stability, military balance, and economic progress in the region."China has stepped up diplomatic and military pressure on Taiwan since the Beijing-sceptic President Tsai Ing-wen took office two years ago, including staging a series of military exercises near the island.

The arms sale coincides with a U.S. decision to issue a visa ban and assets freeze on China's Equipment Development Department and its director, Li Shangfu, over the purchase from Russia of Su-35 combat aircraft in 2017 and S-400 surface-to-air missile system-related equipment this year.

China's purchase of the weapons from Rosoboronexport, Russia's main arms exporter, violated a 2017 law intended to punish the government of Russian President Vladimir Putin for interfering in U.S. elections and other activities. In response, China summoned the American ambassador and defense attache to deliver a protest and recalled its navy commander from a U.S. trip. China's Defense Ministry said the U.S. had no right to interfere in Chinese military cooperation with Russia and demanded the sanctions be revoked. The Kremlin dismissed the sanctions as an "unfair" move to undercut Russia as a major arms exporter.