(CNN) -- The United States and its allies are not willing to hold talks with Iran about its controversial nuclear program in Turkey and will propose another venue instead, diplomatic sources told CNN Tuesday.
Iran on Sunday proposed a new round of talks after more than a year without formal discussions between the Islamic state and the United States, China, Russia, France, the United Kingdom and Germany, a group known as the P5 plus 1.
Iran made the offer through Turkey, a potential host for the talks, Iranian Foreign Minister Manouchehr Mottaki said.
A spokesman for Turkey's Foreign Ministry confirmed to CNN that Ankara, the capital, received a formal request from Iran to hold the next round of talks in Turkey.
The P5 plus 1 will propose another location, but is likely to agree to one of Iran's proposed dates -- November 23 or December 5 -- diplomatic sources told CNN.
Washington and other countries fear Iran wants to develop nuclear weapons technology, but Tehran denies it.
U.S. Defense Secretary Robert Gates said Monday that sanctions aimed at stopping Iran from developing nuclear weapons are having an impact.
"We know that they are concerned about the impact of the sanctions. The sanctions are biting more deeply than they anticipated, and we are working very hard at this," Gates told reporters in Australia.
He said he disagreed with a recent assertion by Israeli Prime Minister Benjamin Netanyahu that a military threat was the only way to influence Iran's nuclear policies.
"I disagree that only a credible military threat can get Iran to take the actions that it needs to, to end its nuclear weapons program. We are prepared to do what is necessary, but, at this point, we continue to believe that the political-economic approach that we are taking is, in fact, having an impact on Iran," he said.
But Gates noted that "when it comes to Iran, all options are on the table."
Iran is now subject to four sets of U.N. sanctions, while the United States and the European Union have also imposed separate penalties on Iran over its refusal to stop enriching uranium.
Still, Iranian President Mahmoud Ahmadinejad has said his country's resolve has not diminished.
"They thought they can weaken the Iranian nation through imposing sanctions and posing threats, but Iranians have showed integrity, convergence and strength," he said in October.
Sen. Lindsey Graham, R-South Carolina, said Saturday the United States should consider neutering Iran's navy and air force if Tehran does not halt its nuclear program.
Speaking at the Halifax International Security Forum in Canada, Graham told reporters that there will come a point where Iran's nuclear program will reach the state that a conventional limited air strike "won't take them out."
"We're probably even past that point," he said. "Instead of a surgical strike on their nuclear infrastructure, I think we're to the point now that you have to really neuter the regime's ability to wage war against us and our allies. And that's a different military scenario.
"It's not a ground invasion but it certainly destroys the ability of the regime to strike back," said Graham, one of his party's top voices on defense.
The talks between Iran and the so-called P5 plus group have been on hold since October 1, 2009, when the two groups last met in Geneva, Switzerland.
CNN's Bharati Naik and Ivan Watson contributed to this report.