Hassan Rohani told reporters Tuesday in Tehran that Iran will only suspend uranium enrichment for the length of international negotiations on the country's nuclear program, which he says should take months, not years.
A U.S. State Department spokesman Richard Boucher said Monday the world must "remain vigilant" about Iran's nuclear ambitions.
He said if Iran fails to uphold the terms of Monday's European-brokered resolution, the International Atomic Energy Agency should immediately refer Tehran to the U.N. Security Council for the possible imposition of sanctions.
Washington has accused Tehran of violating the Nuclear Non-Proliferation Treaty with a secret nuclear weapons development program. Iran has repeatedly denied the charges.
Some information for this report provided by Reuters and AFP.