U.S. President Barack Obama says Iran will face consequences if it fails to show its nuclear program is peaceful and transparent.
President Obama told reporters in Beijing Tuesday that the U.S and China agree that Iran must provide assurance of its peaceful intentions to the international community.
China and the U.S. are among six world powers, known as the P5+1, seeking a negotiated end to Iran's nuclear program.
Mr. Obama said Sunday that Iran is running out of time to respond to a U.N.-backed proposal to ship its low-enriched uranium to Russia for further processing.
Iranian Foreign Minister Manouchehr Mottaki says Tehran would take a positive view of the plan if the uranium swap happens inside Iran.
Speaking to Indian media during his two-day visit to New Delhi, Mottaki said Iran is not willing to send its own nuclear fuel out of the country before receiving the fuel for its Tehran nuclear reactor.
On Monday, the United Nations nuclear agency expressed concerned Iran may still be hiding facilities and details related to its nuclear program.
An International Atomic Energy Agency (IAEA) report said Iran's delayed disclosure of the uranium processing plant near the city of Qom raises questions about the possibility of other undisclosed activities.
Western nations accuse Iran of seeking to develop nuclear weapons, but Iran says its nuclear program is for peaceful purposes.
The U.N. Security Council has already imposed three sets of sanctions on Iran for its refusal to stop its enrichment activities.
On Tuesday, Iran temporarily boosted its gasoline production to show the West it can cope with sanctions targeting its fuel imports. Iran's oil minister, Massoud Mirkazemi, said the move to raise output by 14 million liters a day aims to show Western powers that they cannot use fuel sanctions as a tool against the Islamic republic.
Also, Russian Foreign Minister Sergei Lavrov said there is no link between negotiations with Tehran and a decision not to launch on schedule a nuclear power plant Russia is building in Iran.
Russian state media quote Lavrov as saying "there is no politics involved here" and that the issues are "purely technical."
On Monday, Russia's energy minister, Sergei Shmatko, said the Bushehr nuclear power plant will not start operating by year's end, as previously announced.
An Iranian member of parliament who heads the National Security and Foreign Policy Committee, Alaeddin Bouroujerdi, was skeptical of the Russian move. He was quoted in Iranian media Tuesday as saying "the hasty remarks by Russia do not seem normal."
The plant is meant to run on enriched uranium imported from Russia, rather than on fuel produced in Iran.
Some information for this report was provided by AFP and Reuters.