Crowley said William Burns, the State Department's number three, discussed both "the pressure track and the negotiation track" in a 90-minute conference call with diplomats from China, Russia, France, Britain and Germany.
Crowley said China was represented by its assistant secretary of state for arms control, a level of representation he said Washington is satisfied with.
China is strongly resisting US calls for tougher sanctions against Iran, saying there is still room for diplomacy, particularly after recent comments by President Mahmoud Ahmadinejad.
"They took stock of the recent comments by Iran but also continued to evaluate potential actions on the pressure track," Crowley said.
Ahmadinejad said in a television interview on Tuesday that Tehran would have "no problem" sending abroad its stocks of low-enriched uranium (LEU) to be further purified into fuel.
The International Atomic Energy Agency (IAEA) has proposed, in a bid to allay Western fears, that Tehran ship its LEU to Russia and France to be further purified into fuel for a medical research reactor.
Tehran agreed in principle to the offer during talks with world powers in October, but later appeared to reject the deal and said it preferred a gradual swap for fuel -- preferably on Iranian soil.
US Secretary of State Hillary Clinton said clarification was needed from Iran on its latest offer but said Friday that Tehran has failed to give a proper response to the deal and sanctions should be studied.
During a visit to Paris on Thursday, Chinese Foreign Minister Yang Jiechi argued that Iran had not "totally shut the door" to IAEA efforts to negotiate a deal and argued that diplomacy should be given a chance.
Yang said Friday he hoped a "mutually acceptable formula" could be found to solve the stand-off over Iran's nuclear program, which has entered a "crucial stage."