WASHINGTON (Reuters) -- The United States has dismissed Iranian claims of a leap forward in uranium enrichment and expressed concern that Iran appears to have "unplugged" Google and other Internet service providers.
The White House did not comment directly on Iranian opposition reports of clashes with security forces on the February 11 anniversary of the 1979 Islamic Revolution.
"We continue to monitor events as they happen and try to get the best available information, understanding that a lot of media, Google and other Internet services, have been basically unplugged," White House spokesman Robert Gibbs told reporters.
Separately, U.S. State Department spokesman P.J. Crowley accused Iran of imposing a "near total" blockade on the flow of information in the country, calling it a draconian step.
It was not immediately clear whether the two officials were basing their comments on media reports or independently verified information.
Any clampdown on the Internet would likely fuel tensions between Iran and the international community. The United States and its allies are moving forward with a package of sanctions to punish Iran for its defiance over its nuclear program.
Iranian President Mahmud Ahmadinejad told a rally marking the 31st anniversary of the Islamic Revolution in Tehran that Iran was able to enrich uranium to more than 80 percent purity, but again denied Iran was seeking to build an atomic bomb.
He also said Iran had produced its first batch of higher-enriched uranium fuel, two days after Iran announced the start of the project to increase the enrichment to 20 percent from 3.5 percent.
White House spokesman Gibbs rejected Ahmadinejad's assertions, saying Iran had "made a series of statements that are ... based on politics not on physics."
"The Iranian nuclear program has undergone a series of problems throughout the year. Quite frankly what Ahmadinejad says ... he says many things and many of them turn out to be untrue," he said.
"We do not believe they have the capability to enrich to the degree to which they now say they are enriching."
Gibbs said Iran's resistance to a fuel swap deal brokered by the International Atomic Energy Agency fueled suspicions about the intent of its nuclear program, which Iran insists is for the peaceful generation of electricity.
He said Washington and its allies were looking at a phased approach to imposing new sanctions on Iran, including a U.N. Security Council resolution.
The United States and the other permanent members of the council -- Russia, China, Britain and France -- have not yet agreed on the way forward. China, which has close economic ties to Iran, has stood apart from the other major powers in calling new sanctions premature.
France's UN ambassador said world powers discussing possible new sanctions against Iran should wait for China if necessary.
"It's totally essential to work with the Chinese, even if it means waiting a bit," Gerard Araud told an audience of academics, students and diplomats at New York's Columbia University.
Crowley said a diplomatic solution with Iran was still possible but that Tehran's unwillingness to "engage constructively" had led Washington and its allies to consider pressuring it with further sanctions.