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The Obama administration on Monday said Iran's plan to build 10 more nuclear enrichment  facilities and expand to a half-million centrifuges was "unacceptable" -- but once again, in the face of yet another deadline, it offered no specific response beyond wait-and-see.

On at least four occasions this year, President Obama has set deadlines for Iran to comply with international demands that it demonstrate transparency and cooperation on nuclear developments.

But the Islamic Republic has blatantly ignored all deadlines set by Obama and the United Nations to freeze its uranium enrichment program, prompting critics to say that another "deadline" will have little, if any, impact.

Iran announced ambitious plans Sunday to construct another 10 nuclear facilities after the International Atomic Energy Agency, the U.N.'s nuclear watchdog, called on it to halt work on a uranium enrichment plant.

The Iranian cabinet ordered the Atomic Energy Organization of Iran to begin building enrichment facilities at five sites that have already been studied and to propose five other locations for  construction within two months.

The new sites are to be on the same scale as the site at Natanz, which so far has produced around 3,300 pounds of low-enriched uranium. That is more than enough to produce a nuclear warhead if Iran decides to enrich it to a higher level.

Iran's plan would require it to obtain an additional 500,000 centrifuges, the bulk of which likely would be supplied by Russia. On Monday, Reuters reported that Russia plans to start up Iran's first nuclear power station in March 2010 to coincide with the Iranian New Year -- this despite Russia's joining the IAEA's resolution against Iran on Friday.

Russia's energy minister, who was visiting Iran on Monday, said he's optimistic of a negotiated settlement.

The Obama administration has reacted to Iran's bombast by suggesting that a tougher response from the U.S. and its allies is imminent -- and by blasting the country for choosing to "isolate itself." On Monday, White House Press Secretary Robert Gibbs warned that "time is running out" for the Iranians, while U.S. Ambassador to the U.N. Susan Rice called Tehran's announcement "completely inappropriate" and "unacceptable."

But Iran's blatant disregard for any deadlines set by the administration leaves Obama with few options, former U.S. Ambassador to the United Nations John Bolton said.

"I don't think (Obama) has any options other than the use of force," Bolton told FoxNews.com. "He goes through the motions of saying all options are on the table, but I don't believe that and I don't think the Iranians do either."

Obama has referenced some sort of deadline with respect to Iran's cooperation on several occasions since taking office -- most recently on Nov. 15, when he said after a bilateral meeting with Russian President Dimitri Medvedev that "we are now running out of time."

On Oct. 1, the president said Iran had "two weeks" to grant "unfettered access to IAEA inspectors" following the country's agreement to cooperate with the U.N. watchdog. But one day later, State Department spokesman Ian Kelly said that deadline was "not written in stone" -- and Iran failed to meet it.

Mohamed ElBaradei, chief of the IAEA, then gave Iran until Oct. 23 to respond to a deal to send its uranium abroad for enrichment, and Iranian leaders said on Oct. 25 that they would grant the IAEA access to one nuclear enrichment facility at Qom.

Similarly, Obama said on July 10 that the Iranians had until the G-20 summit on Sept. 24 to demonstrate that their nuclear enrichment program is intended for peaceful purposes -- a deadline that that came and went with no acknowledgement.

"We've offered Iran a path towards assuming its rightful place in the world...We hope Iran will make the choice to fulfill them, and we will take stock of Iran's progress when we see each other this September at the G-20 meeting," Obama said.

On May 18, following a meeting with Israeli Prime Minister Benjamin Netanyahu, Obama stressed the importance of setting a "clear timetable" for Iranian cooperation, adding that "we should have a fairly good sense by the end of the year as to whether they are moving in the right direction and whether the parties involved are making progress and that there's a good faith effort to resolve differences."

Iran so far has not acted on a deadline set forth by the "P5+1," composed of the five members of the U.N. Security Council -- China, France, Russia, Britain and the U.S. -- plus Germany, to send 1.2 tons of low-enriched uranium to Russia by the end of the year.

State Department spokesman Ian Kelly told reporters Monday that the U.S. has been talking with its allies about alternatives if the diplomatic track fails, but didn't think it is time to talk about "specific sanctions."

"We've been pursuing the engagement track and we've made some really good proposals...and they haven't responded," he said during a press conference. "If they can't respond positively to this offer, we're going to have start shifting to the other side, the pressure track. I don't think it's productive of me to get into the additional measures we would take."

Bolton, who served as U.N. ambassador under President George W. Bush, said those and other efforts have not yielded any compromise from Iran.

"We've wasted so much time through the European Union efforts at negotiation that the only other option is the pre-emptive use of military force. If you don't think Obama really is considering that seriously, then that brings the decision down to Israel to see what they do."

The Israelis have repeatedly suggested that the failure of diplomacy is not the end of the line, and it has shown restraint in the issue. Still, a top Israeli diplomat said Sunday that other cards aren't off the table.

"This is an evil regime that must be stopped," former Israeli Ambassador to the U.N. Dan Gillerman said. "And if diplomacy doesn't stop it, other means will have to be taken."

Bolton said that the White House's "or else" warning to Iran will likely take the form of more economic sanctions, which Bolton claims will have no effect.

"We are well past the point where economic sanctions could actually achieve the objective of stopping the Iranian nuclear program," he said. "If Obama begins to pursue sanctions, that's just going to lead to further delay.

"If there is a point at which military force is still possible to break Iran's control over the nuclear fuel cycle, this is it," he added, saying that the most viable option is to "break Iran's indigenous control over the nuclear fuel cycle at one or more key points."

The Associated Press contributed to this report.