BEIJING - China's foreign ministry rebuked the US Congress on Monday after legislators passed a bill allowing the sale of second-hand warships to Taiwan, the self-ruled island which Beijing claims as a renegade province.
The US Senate unanimously approved the bill last week, authorising the sale of four Perry-class guided missile frigates to Taiwan. China expressed anger in April when a similar bill passed in the US House of Representatives.
China and Taiwan have been ruled separately since defeated Nationalist forces fled to the island at the end of a civil war with the communists in 1949. China has never renounced the use of force to bring Taiwan under its control.
Foreign Ministry spokesman Hong Lei said the bill's passage was an "interference" in China's internal affairs.
"China is resolutely opposed to this and has already made solemn representations to the US side. We hope the US Congress stops carrying forward this legislation," Hong told reporters at a regular press briefing.
"We also hope the newly elected authorities can prevent the implementation of this legislation to avoid influencing the development of China-US relations," Hong said.
The bill, which includes provisions on the transfer of warships to Mexico, Thailand and Pakistan, still has to be signed into law by US President Barack Obama.
US weapons sales in recent years to Taiwan have attracted strong condemnation in China, but have not caused lasting damage to Beijing's relations with either Washington or Taipei.
Under the Taiwan Relations Act, enacted in 1979 when Washington severed formal ties with the island in favour of recognising the People's Republic of China in Beijing, the United States is obligated to come to Taiwan's aid in the event of an attack.
While Taiwan and China have signed a series of landmark trade and economic agreements since 2008, political and military suspicions are still deep, especially in democratic Taiwan where many fear China's true intentions.
China's military modernisation has also been accompanied by a more assertive posture in its regional territorial disputes.