Israeli Prime Minister Benjamin Netanyahu warned on Sunday that Iran would be on the brink of nuclear weapons capability in six to seven months, adding new urgency to his demand that President Barack Obama set a clear "red line" for Tehran in what could deepen the worst U.S.-Israeli rift in decades.

Taking his case to the American public, Netanyahu said in U.S. television interviews that by mid-2013, Iran would be 90 percent of the way toward enough enriched uranium for a bomb. He urged the United States to spell out limits that Tehran must not cross or else face military action - something Obama has refused to do.

"You have to place that red line before them now, before it's too late," Netanyahu told NBC's "Meet the Press" program, saying that such a U.S. move could reduce the chances of having to attack Iran's nuclear sites.

The unusually public dispute - coupled with Obama's decision not to meet with Netanyahu later this month - has exposed a deep U.S.-Israeli divide and stepped up pressure on the U.S. leader in the final stretch of a tight presidential election campaign.

The message implicitly fit in with Romney's harsh rhetoric on Iran. Romney, like Obama, has said he would not allow Iran to add a nuclear weapon to its arsenal. The Republican nominee has been critical of Obama for not acting quickly or forcefully enough, but has not offered specifics about what he would do that is different. Neither Obama nor Romney have called for U.S. military intervention any time soon.

Obama insists that time remains for tough sanctions imposed by the U.S. and its allies to force a diplomatic solution. Netanyahu argues time is running out and that Washington must quickly draw "red lines" past which Iran cannot move in its nuclear program without engendering an American military attack.

Netanyahu has threatened that Israel would attack Iran alone if it determines Tehran is reaching a point beyond which the Israeli military could do little to stop the march toward building a nuclear weapon.

The United States, its Western allies and Israel all accuse Iran of using what it says is a nuclear program designed only for electricity generation and medical research as cover to build a weapon.

The savvy Netanyahu, who lived many years in the United States and once worked at the same financial firm as Romney, denied he was intervening in the U.S. presidential race. He and Obama have a cool relationship, and earlier this summer he accorded Romney the trappings of a visiting head of state when the candidate made a gaffe-filled foreign tour to build his standing on foreign policy.

As Muslim demonstrators threaten U.S. diplomatic missions throughout the Islamic world, Netanyahu's remarks on NBC sought to draw on the violence to bolster his argument.

"Iran, with nuclear weapons, would mean that the kind of fanaticism that you see storming your embassies would have a nuclear weapon. Don't let these fanatics have nuclear weapons," he said.

That came on the heels of renewed and untrue Romney assertions that Obama had run a foreign policy in the Islamic world that was based on apologies for past American actions, especially in the Arab world. Romney then amped up his criticism in the first hours of the start of the current chaos at U.S. embassies, by ill-timed remarks that the Obama administration was not standing up for U.S. ¬ideals.

He spoke before an assault on the U.S. embassy in Cairo and the attack on the consulate in Benghazi, Libya, in which Ambassador Christopher Stevens and three other Americans were killed. Romney came under heavy political fire for those remarks and even sterner comments the next day. He was blasted by Democrats and some Republicans for issuing statements before he knew the facts and for breaking with the U.S. tradition of bipartisanship in times of foreign crises.

Romney and his surrogates also have been deeply critical of Obama's handling of U.S.-Israeli relations, with some Republican surrogates saying the administration has "thrown Israel under the bus."

Netanyahu denied he was joining that argument. Asked if he viewed Romney as the candidate who would keep Israel safer, the Israeli leader told NBC:

"God, I'm not going to be drawn into the American election. And what's guiding my statements is not the American political calendar, but the Iranian nuclear calendar."

But his appearance on widely viewed and important U.S. television news programs when he did, whether knowingly or not, could affect the outcome of the race.

While the struggling U.S. economy is the top issue among American voters, much of Romney's most conservative base, especially evangelical Christians, are determined to tie the United States even more closely to the needs of Israel.

Netanyahu contends Iran poses an existential threat and would use a nuclear weapon to make good on his rhetorical threats to wipe Israel off the map.

While polls show Obama gaining ground on Romney's standing among voters as the best candidate to handle the economy, the president holds a significant lead as the best man to run U.S. foreign policy.

Romney sees the turmoil in the Islamic world and attacks on U.S. embassies as an opportunity to cut into that advantage. He no doubt is taking pleasure, as well, over the timing of Netanyahu's remarks and the audience he was addressing.