US President Barack Obama said Sunday time was running out for diplomacy in a dispute over Iran's nuclear program, but a top Iranian official said it was up to the West to show it sincerely wanted a deal. Russia and France, both involved in talks with Iran over what the West fears are its plans for an atomic bomb, also put pressure on Tehran, with French Foreign Bernard Kouchner saying the republic looked set to reject a UN-drafted accord. Obama suggested patience was running low in the dispute with Iran, which faces possible harsher international sanctions or even Israeli military action. “Unfortunately, so far at least, Iran appears to have been unable to say yes to what everyone acknowledges is a creative and constructive approach,” Obama said after talks with Russian President Dmitry Medvedev on the sidelines of an Asia-Pacific summit in Singapore. “We are running out of time with respect to that approach.” Repeating previous Russian language, Medvedev said “other means” could be used if discussions did not yield results, but did not specify what they might be. A draft deal brokered by the UN's nuclear watchdog, the International Atomic Energy Agency (IAEA), calls on Iran to send some 75 percent of its low-enriched uranium (LEU) to Russia and France to be turned into fuel for a Tehran medical research reactor. A senior adviser to Iran's President Mahmoud Ahmadinejad said no official response to the proposal had been announced. “We are waiting to see how much sincerity the Western countries have in their pledges,” said Mojtaba Samareh-Hashemi. Iranian officials have said Tehran prefers to buy reactor fuel from foreign suppliers rather than part with its LEU, or at most swap small amounts of LEU for the reactor material on Iranian soil.