WASHINGTON - US Secretary of State Hillary Rodham Clinton warned Sunday that Iran may "pull some stunt" in the next few days as the Islamic republic prepares for the possibility of mroe United Nations sanctions over its nuclear program."They have consistently tried to avoid being held accountable," Clinton told reporters before leaving on a trip to Latin America.RELATED:Mottaki humiliated at European ParliamentReport: Iran hid equipment from inspectors'Iran critics must get rid of nukes'The US suspects Iran is enriching uranium to build a nuclear warhead. Teheran denies the charge and insists on its right to a peaceful nuclear power program.The US hopes to bring a fourth sanctions resolution to a UN Security Council vote this week."I fully expect Iran to pull some stunt in the next couple of days because they know that sanctions are on the way," Clinton said Sunday."I think we will see something coming up in the next 24 to 48 hours where Iran says, 'Wait a minute, wait a minute, look at what we're going to do now,'" she added. Iran is just one of the issues Clinton will discuss with Latin American leaders during this week's trip. She is expected to press Brazil, which opposes UN penalties against Iran, to switch sides.Brazil, an elected member of the UN Security Council, recently worked with Turkey to broker an agreement with Iran aimed at averting fresh penalties.