"We have already begun discussions with our partners and with like-minded nations about pressure and sanctions," US Secretary of State Hillary Clinton said at a news conference with Qatari Prime Minister Sheikh Hamad bin Jassim al-Thani.
"Our goal is to pressure the Iranian government, particularly the Revolutionary Guard elements, without contributing to the suffering of the ordinary (people), who deserve better than what they currently are receiving," she added.
Clinton said the United States, which accuses Iran of secretly pursuing nuclear arms under the cover of its civil nuclear program, will continue its "dual-track" approach of seeking an end to the program through negotiations while also considering sanctions as a way to change Tehran's policy.
Iran has rebuffed the West's year-end deadline to accept an enrichment fuel deal aimed at quelling international fears it is trying to build nuclear weapons, something Clinton said disappointed the Obama administration.
She also said Washington was "disturbed by the mounting signs of ruthless repression" that the Iranian authorities have shown in cracking down on protests against the leadership since a disputed election in June.