Updated

The chaos in Iran stemming from last week's disputed election may ultimately crush any hopes the Obama administration has for engaging the country in the near term, insiders and analysts warned.

Since taking office, President Obama has tried to reach out to the Iranian public and government, declaring that he's willing to engage any regime that will "unclench" its fist -- Iran was a primary target of that message.

But while Iranian President Mahmoud Ahmadinejad acted unreceptive to the overture before, the government is behaving flat-out hostile now that the U.S. administration is criticizing the Iranian regime for its crackdown of pro-reform demonstrators. And analysts warn that regardless of Ahmadinejad's stance, Obama may want to reconsider his engagement aims since Ahmadinejad's legitimacy as president has been thrown into question.

Barring a regime change, the restoration of U.S.-Iran ties looks very much in doubt, analysts say.

"This is obviously the wrong time to be sitting across the table from representatives of this government, let alone offering them incentives," said Kristen Silverberg, former U.S. ambassador to the European Union. "I think that anything like that right now could really take the wind out of the sails of this reform movement. This is really the wrong time," she said.

Silverberg said Obama should "revisit" his engagement goals and instead talk with European allies about tightening sanctions against the regime.

Rep. Pete Hoekstra, R-Mich., on Sunday accused Obama of "stubbornly" holding onto the belief that negotiations with the current regime are the best way forward.

But U.S. officials privately concede that the turmoil in Iran has created an irrevocable setback for engagement.

Observers see the nail in the diplomatic coffin as Supreme Leader Ayatollah Ali Khamenei's hard-line speech Friday, in which he demanded opposition leaders end protests or be held to account for "bloodshed and chaos" -- U.S. officials viewed that address as "stunning" in its stridency and authoritarianism.

The regime is forcefully asserting its authority, and defiantly rejecting any international criticism of the way it is battling protesters on Iran's streets. Though GOP critics say Obama is not showing enough support for the protesters, the Iranian regime already is accusing the United States of meddling.

On Sunday, Ahmadinejad reportedly warned the United States and Britain to "correct" their "interfering stances," insisting that they "will not be placed in the circle of friendship with the Iranian nation" given their leaders' remarks.

According to an Iranian government Web site, Iran's parliament speaker, Ali Larijani, on Sunday also accused the Obama administration of "opportunistic and imperialistic gestures."

"You exposed the deceitful meaning of change very soon," he said.

Larijani reportedly called the stances of the United States and its allies "shameful" and urged the government to reconsider ties with European nations that have spoken out against the regime. The United States and Iran do not have ties.

Sen. Richard Lugar, R-Ind., said it's "totally improbable" that Iranian leaders would call a meeting with U.S. officials in light of the turmoil -- but he said the United States should not take direct talks with Iran off the table.

"We would sit down because our objective is to eliminate the nuclear program that is in Iran," he told CNN's "State of the Union."

Rep. Michael Turner, R-Ohio, said regardless of what happens, the United States cannot walk away from its demands on Iran to cut ties with Hamas and Hezbollah and abandon its alleged pursuit of nuclear weapons.

But he acknowledged the hardship the United States will have in attempting to engage the current regime at this point.

"If Ahmadinejad turns out to be the victor, it's going to be very difficult for the United States to sit across the table and see him as the legitimate ruler," Turner said.

FOX News' James Rosen contributed to this report.