The White House expressed confidence Friday that American intelligence will know if Iran escalates its nuclear program in a sprint to build an atomic bomb—a day after Israel's defense minister warned that the allies might not know "in time" to prevent it.

"We have eyes, we have visibility into the program," press secretary Jay Carney told reporters at his daily briefing. "We feel confident that we would be able to detect a break-out move by Iran towards the acquisition of a nuclear weapon."

"We believe there continues to be the time and space to pursue this course," Carney said, referring to punishing American and international economic sanctions on the Islamic republic. "It is the best course of action to ensure that Iran does not obtain a nuclear weapon. We take no options off the table, and we consult with our allies all the time about the situation in Iran with regards to this program."

But Carney's professed confidence about the quality of the information regarding Iran's nuclear program, widely seen by American and Israeli officials as an attempt to acquire the ability to build a nuclear weapon, appeared to conflict sharply with Israeli Defense Minister Ehud Barak's just a day earlier.

Barak told Israel Radio that news reports of a new American intelligence assessment that Iran has made surprising progress towards a nuclear weapon makes it "less clear and certain that we will know everything in time about their steady progress toward military nuclear capability."

Israel has warned that it views a nuclear-armed Iran as a threat to its very existence and reserves the right to use military force against Tehran's atomic program. Carney's reference to taking "no options off the table" is diplo-speak for the same thing—but where Israeli officials have been ramping up their public warnings about possible military action, their American counterparts have steadfastly insisted that there is time yet to tighten the economic vise further on Iran in hopes of a diplomatic breakthrough.

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"We work very closely with our Israeli counterparts on this issue. We share information as a matter of course, and we share an assessment of where Iran is, and what its capacities are, and what the timelines look like," Carney said Friday. He noted that "international inspectors" from the U.N. nuclear watchdog agency have had access to key atomic sites in Iran.

"It is our firm belief that there is time and space to pursue the diplomatic option that includes an extremely, and increasingly, aggressive sanctions, includes diplomatic isolation, and international condemnation," he said.

Mitt Romney has repeatedly accused Obama of being weak in the face of Iran's defiance of international pressure—but has not spelled out a policy that differs in any meaningful way from the incumbent's approach. Still, aides to the president are mindful of the potential political dimension in attacks claiming that there is daylight between the United States and Israel.

On Thursday, Israel's Haaretz newspaper reported that Obama had received a new National Intelligence Estimate (NIE)—the consensus assessment of the American intelligence community—that "Iran has made surprising, notable progress in the research and development of key components of its military nuclear program." The daily cited unnamed "Western diplomats and Israeli officials."

Carney declined to comment on the news report, but some American officials bristled at what they saw as a naked Israeli effort to pressure Washington into taking a more hawkish line.

If the Haaretz report is correct, the new NIE would be yet another shift in American intelligence agencies' assessment of just what Tehran is doing—though nothing so momentous as an NIE compiled in 2007. That report said Iran had halted its military nuclear program in 2003 and that there was no clear evidence that those efforts had resumed. The NIE came in the aftermath of the Iraq War intelligence debacle, in which the United States incorrectly insisted Saddam Hussein had weapons of mass destruction. Iran flatly denies that it seeks nuclear weapons and insists that it aims only to bolster its ability to produce energy for civilian purposes.

Some American officials say that Iran wants the ability to build a nuclear weapon, not necessarily to actually acquire an atomic arsenal.

Director of National Intelligence James Clapper told the Senate Intelligence Committee in January that: "We assess Iran is keeping open the option to develop nuclear weapons, in part by developing various nuclear capabilities that better position it to produce such weapons, should it choose to do so. We do not know, however, if Iran will eventually decide to build nuclear weapons." He underlined that Iran was guided by a rational "cost-benefit" approach that he said gave the international community leverage to shape Tehran's decision.

While Republicans have accused Obama of shortchanging the security of Israel—thought to be the region's only, and undeclared, nuclear power—they have also loudly complained about national security disclosures regarding an unprecedented cyberwar effort by the Obama administration to sabotage Iran's atomic program.