Washington wants progress on an investment treaty with Beijing before it considers expanding an eventual Pacific-region trade pact to include China, a top U.S. official said on Thursday.
U.S. Trade Representative Michael Froman said the United States was open to other countries joining the Trans-Pacific Partnership (TPP) being negotiated by Washington and 11 other nations.
However, before China can be considered, Washington wants movement on a bilateral investment treaty.
"We'll want to see whether we can make progress there first," Froman said during the World Economic Forum in Davos, Switzerland.
Beijing said in May it would consider joining the TPP, which would establish a free-trade bloc stretching from Vietnam to Chile and Japan, encompassing about 800 million people and almost 40 percent of the global economy.
Other countries, including South Korea, have also expressed interest in joining, although Washington has said they would have to wait until the current negotiators reach a deal.
Washington had hoped for a deal by the end of 2013, but that did not happen in part because of differences over farm tariffs between the United States and Japan.
The countries already in the talks are the United States, Canada, Japan, Australia, New Zealand, Singapore, Malaysia, Brunei, Vietnam, Chile, Mexico and Peru.
The United States and China agreed in July to restart stalled negotiations on an investment treaty, with Beijing dropping efforts to protect some sectors of its economy.
Froman said the renewed talks with Beijing would be part of a larger agreement.
"That's where I think our focus should be because those are key elements of any investment chapter," he added.