* Obama vows new Iran push in coming months
* President sees window of time for diplomacy
* Syria umbrella group is legitimate, but not an exile government
By Paul Eckert
WASHINGTON, Nov 14 (Reuters) - President Barack Obama said on Wednesday that he will renew efforts for a diplomatic resolution to Iran's suspected attempt to build a nuclear weapon, but denied that any talks with Tehran were imminent.
Obama told a news conference that reports that emerged before his re-election on Nov. 6 of impending U.S. talks with Iran were "not true and ... are not true as of today." But he said diplomacy remains his preferred option.
"I will try to make a push in the coming months to see if we can open up a dialogue between Iran and - not just us but the international community - to see if we can get this thing resolved," he said.
"We're not going let Iran get a nuclear weapon, but I think there is still a window of time for us to resolve this diplomatically," added Obama.
"I can't promise that Iran will walk through the door that they need to walk through, but that would be very much the preferable option," he said.
Tehran denies U.S. and Israeli allegations it is seeking a nuclear weapons capability, saying its program is entirely peaceful. But U.N. inspectors suspect past, and perhaps ongoing, military-related nuclear work is geared toward building a bomb.
Obama said tough economic sanctions imposed by Western nations were hurting Iran's economy and he believed Iranians could find a way to use nuclear energy peacefully while assuring the world that it is not trying to build a weapon.
In another sign diplomacy between Iran and major powers may be poised to resume, diplomats in Washington said officials from five major world powers and Germany planned to meet next week, possibly in Brussels, to chart strategy for a new round of talks with Iran.
The diplomats, who spoke on condition of anonymity, said that Britain, China, France, Russia, the United States and Germany - a group collectively known as the P5+1 - planned to send their foreign ministry political directors to the talks.
IAEA REPORT ON IRAN DUE FRIDAY
In October, diplomats had said they were considering asking Iran for stricter limits on its nuclear program in exchange for an easing of sanctions in a long-shot approach aimed at yielding a solution that has eluded them for more than a decade.
One option could be for each side to put more on the table - both in terms of demands and possible rewards - than in previous meetings in a bid to break the stalemate despite deep skepticism about the chances of a breakthrough any time soon.
The U.N. International Atomic Energy Agency (IAEA) is expected to submit its next quarterly Iran report to member states on Friday, 10 days after Obama's re-election raised hope of a revival of diplomacy after hawkish campaign talk and speculation that Israel might strike Iranian nuclear facilities.
The report is expected to show a defiant Iran pressing ahead with expanding its controversial nuclear program, despite harsh Western sanctions targeting its vital oil sector, and continuing to sanitize a military site the IAEA wants to visit.
On the crisis in Syria, Obama welcomed the recent formation of an umbrella group for the Syrian opposition fighting the regime of President Bashar al-Assad, but he stopped short of recognizing it as a government in exile.
"I'm encouraged to see that the Syrian opposition created an umbrella group that may have more cohesion than they've had in the past," said the president.
"We consider them a legitimate representative of the aspirations of the Syrian people. We're not yet prepared to recognize them as some sort of government in exile, but we do think that it is a broad-based representative group," he said.
Obama said he also shares Israel's concern about the movement of chemical weapons in Syria during the current fighting and turmoil.