"We've indicated that our trade relationship with China is entering into a new era, a new phase" where we expect them to live up to the obligations they made when they joined the WTO in December 2001, Deputy US Trade Representative Karan Bhatia told Reuters in an interview.

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"I really do want to take on the notion that somehow using the WTO dispute settlement process is something that should unsettle the trade relationship," Bhatia said. "This is a responsible and mature way to deal with issues that have not managed to be resolved through other dialogue."

Bhatia spoke just hours after the United States took action at the WTO against China for alleged piracy and counterfeiting of US goods and blocking access American movies, music, books and other publications.

Charging that China was breaking its 2001 entry agreement, Washington sought consultations with Beijing over its twin complaints, which could lead to a formal case being brought if no deal is struck within 60 days.

China responded quickly to the action, which it said threatened to damage an ongoing dialogue between the two countries.

Bhatia said he had not seen those comments, but noted that other countries have challenged the United States 34 times at the WTO since China joined in 2001 without raising fears that "trade relations are falling apart."

The US action -- along with worries about the health of the housing market -- helped push the dollar to a two-year low against the euro as traders worried it was a sign of increased protectionism.

Bhatia denied the White House was bowing to congressional pressure to take tougher action to rein in the US trade deficit with China, which hit a record $232 billion in 2006.

"This is not some knee-jerk reaction to sentiment on the Hill. This is part of a very carefully thought-through process," he said.

In a February 2006 top-to-bottom review of trade relations with China, the Bush administration warned Beijing that a grace period for implementing its WTO commitments was over, Bhatia said.

In the current phase of relations, "We need to work with them as a mature trading partner and as fully acceded member to the WTO ... Part of that equation is going to be an intense process of dialogue. Part of it also is going to be ... a stronger focus on enforcement," he said.

"I don't see (the new trade cases) as something that's going to impede a deep and growing US trade relationship with China. I see this step as something that's going to help resolve important, but discrete, points of disagreement with China."

Sherman Katz, a trade scholar at the Carnegie Endowment for International Peace, said the Bush administration needed to "show a little more spine" in dealing with China to prevent Congress from taking even stronger action and accomplish other legislative trade goals.

"I think we'd be naive if we didn't look at the overall political landscape," Katz said. "This certainly a much better step than some kind of across-the-board tariff of all Chinese goods," as some in Congress have proposed to rein in the huge trade deficit.