A US official called Thursday on China not to punish companies over arms sales to Taiwan, and said it was too early to determine the extent of the rift between the two nations.

David Shear, the State Department pointman on China, said the US government was consulting with companies which are being threatened with sanctions by Beijing for involvement in the 6.4 billion-dollar arms package to Taiwan.

"We would certainly regret any Chinese effort to restrict American business practices," Shear, the deputy assistant secretary of state for East Asian affairs, told a hearing in Congress.

But he noted that China had not yet acted on its threats.

"The Chinese reaction has been within expected parameters," Shear said.

"We're going to watch to see what the Chinese do and consult with the firms concerned and take it from there," he said.

The United States last week defied warnings from China and approved the package which includes Patriot anti-missile defenses and Black Hawk helicopters.

China, which claims the island, took the usual step of suspending military ties with the United States and also threatened to retaliate against the individual firms.

US defense contractors sell little to China, which has been under a US and EU weapons embargo since its military crushed pro-democracy campaigners in Tiananmen Square in 1989.

But units of aerospace giant Boeing Co. and conglomerate United Technologies Corp. are involved in the sale. Both firms have longstanding interests and cooperation with China.

Taiwan is among a series of issues clouding relations between the United States and China.

President Barack Obama is expected to meet later this month with Tibet's exiled spiritual leader the Dalai Lama despite Chinese protests.

Washington is also supporting US Internet titan Google as it threatens to pull out of China over what the company said were cyberattacks against human rights activists.

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