US political heat on China intensified yesterday after Barack Obama, president, raised the issue of a weak Chinese currency a day after the US Senate condemned cyberattacks on Google.

Speaking to Senate Democrats yesterday, Mr Obama warned that the US should not back down from trade with China.

“For us to close ourselves off from that market would be a mistake,” he said. But he added that currency rates needed to be addressed internationally “to make sure our goods are not artificially inflated in price and their goods are artificially deflated in price”.

Tensions between Washington and Beijing have risen in the wake of a $6.4bn (€4.5bn, £4bn) US arms deal with Taiwan and ahead of an expected meeting this month between Mr Obama and the Dalai Lama, the Tibetan spiritual leader.

US senators on Tuesday voted unanimously to condemn the cyberattacks on Google and other companies that caused the search engine group to threaten to quit China.

“It is important that the US not stand idly as China infringes on the free flow of information,” said Arlen Specter, the Pennsylvania Democrat.

A senior Democratic senator also asked 30 large technology groups to provide details of their human rights practices in China.

Dick Durbin, the Illinois senator and assistant majority leader, sent a sharply worded request for information to US groups such as Facebook, Apple, IBM, Amazon and Oracle and to international companies including Nokia, Vodafone, SAP, RIM and Toshiba.

He said Google set “a strong example in standing up to the Chinese government's continued failure to respect the fundamental human rights of free expression and privacy. I look forward to learning more about whether other . . . companies are willing to follow Google's lead”.

Mr Durbin said he expected the responses to include information on the companies' business in China and any efforts to ensure their products and services did not “facilitate human rights abuses by the Chinese government”.

Next week the congressional executive commission on China, which was created in 2000 to coincide with the country's accession to the World Trade Organisation, will hold a hearing focused on the cyberattacks, including the intellectual property protection issues that it raised.

Dennis Blair, the US's director of national intelligence, highlighted China's “growing international confidence and activism” in testimony to Congress this week.

But he added that Beijing's policies were largely set by its commercial interests and that its “core priority remains ensuring domestic stability”.

In his evidence, Mr Blair listed the global “cyberthreat” to the US ahead of all other threats Washington faced. He described the recent cyberattacks on Google as “a wake up call to those who have not taken this problem seriously”.