The United States will push for more U.N. Security Council sanctions against Iran if Tehran continues to ignore council demands for suspension of the country's uranium enrichment program, the State Department said Monday.

Department spokesman Sean McCormack said Iran appears to be continuing "down the path of isolation" by its recent announcement of stepped up installation of centrifuges that process uranium gas into fuel that can be used for weapons or generating energy.

McCormack said the U.S. would seek "incremental" sanctions at the U.N. should the standoff continue, though he did not specify what they might be or the exact timing of any action.

The U.N. Security Council approved economic sanctions on Iran on Dec. 23 due to its refusal to halt uranium enrichment. If Tehran fails to comply by the end of a 60-day deadline that the U.N. imposed, the Security Council will consider new measures.

Tehran already has cascades of 164 centrifuges installed above ground at Natanz, and has announced plans to operate 3,000 centrifuges below ground there, enabling it to speed up production of nuclear fuel.