Spokesman Kurtis Cooper said Undersecretary of State Nicholas Burns and political directors from China, Russia, France, Britain and Germany were due to hold discussions after a two-hour phone session on Thursday.
He did not say exactly when the new phone conference would be held.
The State Department on Thursday reported the six countries had made progress towards reaching consensus on a new, tougher text against Iran for its refusal to give up uranium enrichment work that Washington fears could lead to a nuclear bomb.
US officials said only a few issues remained to be nailed down and expressed hope that UN ambassadors from the six countries could begin drafting a new resolution next week.
Senior US and European officials had indicated Friday that new UN sanctions being drawn up against Iran to curb its nuclear program would involve only a relatively minor tightening of measures imposed by the world body in December.