The US has expressed scepticism over Iran providing any "serious response" to concerns raised by the international community about its controversial nuclear programme until the UN security Council imposes sanctions on it.
"I have told my counterparts in many capitals around the world that I believe that we will not get any serious response out of the Iranians until after the (UN) Security Council acts," Clinton said at a joint news conference with visiting new British Foreign Secretary William Hague.
Clinton said she is not expecting much progress in this weekend's visit of the Turkish and Brazilian leaders to Tehran, as both the US and Britain believe Iran is determined to pursue its nuclear weapons programme.
External Affairs Minister SM Krishna is also scheduled to pay a visit to Iran.
State Department spokesman PJ Crowley separately told reporters that he is not aware if the US has reached out to India on the Iranian issue.
In the past two days, Clinton has made personal telephone calls to the Foreign Ministers of the Turkey and Brazil to tell them that Iran is not meeting its international obligations.
Any attempt by the leaders of Turkey and Brazil to convince Iran to give up its nuclear weapons programme and come to the dialogue table, Clinton observed, would be just like climbing a hill.
"We are making progress every day. This is the highest priority, not only of the United States but of many of our partners and allies like the UK. We believe that the case is being made perhaps most effectively by the Iranians themselves," she said.
Clinton also pointed out that the Iranians were not responding to the offers of engagement.
The Secretary of State said Brazilians are still hopeful that they would "climb the hill" to convince Iran to join the P5 Plus 1 (US, UK, France, Russia and China plus Germany) negotiation process.
"So the world leadership, as evidenced by the Security Council, has moved in the same direction -- some perhaps more quickly than others -- but in the direction of reaffirming the authority of the Security Council, of putting some real teeth into the sanctions, of uniting the world in a way that will send an unequivocal message to the Iranian leadership," she said.