Top State Department and foreign ministry officials from the United States, Britain, China, France, Germany and Russia will debate further UN Security Council action to halt Iran's sensitive nuclear work, the official said.
"We have a political directors phone call that will probably take place in the next several days. It hasn't been finally nailed down yet in terms of timing," said the official who was speaking on the condition of anonymity.
William Burns, the third-ranking official at the State Department, and his colleagues will discuss "next steps in the UN Security Council," the official said.
On the sidelines of the UN General Assembly in New York on September 29, US Secretary of State Condoleezza Rice said the six powers would "move forward" with further measures against Iran over its nuclear defiance.
She spoke two days after the 15-member Security Council unanimously adopted a resolution urging Iran to suspend its sensitive nuclear fuel work, but offering no new sanctions and merely reaffirming existing ones.
The United States and its European allies had pushed for new, tougher sanctions against Tehran but ran into resistance from Russia and China.
The UN Security Council has already imposed three sets of sanctions on Iran for its refusal to heed international calls to stop uranium enrichment.
The West and Israel have accused Iran of using its nuclear program as a cover to build nuclear arms. But Tehran insists its program is strictly peaceful and solely aimed at generating electricity.
