The White House on Saturday denied a New York Times report that Iran had agreed to hold direct negotiations over its nuclear program, but said it would be willing to hold bilateral talks with Tehran.

On Sunday, NBC News reported, based on an anonymous “senior administration official,” that back channel talks had taken place, but no meeting had been finalized.

Responding to the New York Times report, which cited unnamed administration officials, National Security Council spokesman Tommy Vietor said the US had been willing for years to hold bilateral talks with Iran.

“It’s not true that the United States and Iran have agreed to one-on-one talks or any meeting after the American elections,” Vietor said in a statement.

“We continue to work with the P-5 on a diplomatic solution and have said from the outset that we would be prepared to meet bilaterally. The president has made clear that he will prevent Iran from getting a nuclear weapon, and we will do what we must to achieve that. It has always been our goal for sanctions to pressure Iran to come in line with its obligations. The onus is on the Iranians to do so, otherwise they will continue to face crippling sanctions and increased pressure.”

The New York Times report claimed that the agreement was a result of secret exchanges between officials of both countries dating back to the beginning of President Barack Obama’s term, but that Iranian officials insisted that direct talks wait until after the upcoming presidential election so they would know who they would be negotiating with.

Following the White House’s denial, the New York Times added the words “in principle” to describe the agreement.

The report also noted Israel’s response to the said agreement to meet. Israel’s Ambasador to the UN Michael Oren reportedly said the administration had not informed Israel about the agreement, and that the Israeli government feared the Iranians would use new talks to “advance their nuclear weapons program.”

“We do not think Iran should be rewarded with direct talks,” Oren was quoted as saying, adding that Israel preferred tougher sanctions over direct negotiations.

Western nations and particularly Israel, which Iranian leaders have repeatedly threatened to “wipe off the map,” fear the Islamic republic is determined to develop nuclear weapons and fundamentally reshape the balance of power in the Middle East. Iran has long maintained that its program is for peaceful energy and research purposes.

Prime Minister Benjamin Netanyahu has repeatedly called on the international community to set red lines for Iran’s nuclear development, and to back them up with credible threats of military intervention.

Obama and Republican presidential candidate Mitt Romney will meet Monday night in a debate focusing on foreign policy.

Obama has said he’ll prevent Iran from acquiring nuclear weapons. He hopes sanctions alongside negotiations can get Iran to halt uranium enrichment. But the strategy hasn’t worked yet. Obama holds out the threat of military action as a last resort.

Romney has accused Obama of being weak on Iran, saying the US needs to present a more credible military threat.

Despite unprecedented global penalties, Iran’s nuclear program is advancing as it continues to defy international pressure, including four rounds of sanctions from the U.N. Security Council, to prove that its atomic intentions are peaceful.

Those sanctions, coupled with tough measures imposed by the United States and European nations are taking their toll, particularly on Iran’s economy. Iranian authorities have in recent weeks been forced to quell protests over the plummeting value of the country’s currency. The rial lost nearly 40 percent of its value against the U.S. dollar in a week in early October, but has since slightly rebounded.

U.S. officials say they are hopeful that pressure from the sanctions may be pushing Iran’s leaders toward concessions, including direct talks with the United States. But several said on Saturday that they did not believe such discussions would happen any time soon.

If one-on-one talks are to occur, they would likely follow the model that the U.S. has used in six-nation nuclear disarmament talks with North Korea, the officials said.

In those discussions, U.S. negotiators have met separately with their North Korean counterparts but only as part of the larger effort, which also involves China, Japan, South Korea and Russia. Direct U.S.-North Korean talks are preceded and followed by intense consultations with the other members of the group.

However, the direct talks with North Korea have yet to bear fruit and U.S. officials warned that talks with Iran may not yield anything either. If U.S.-Iran talks do occur, they would likely be part of the P5+1 process, which groups the Britain, China, France, Germany, Russia and the United States and is overseen by the European Union. The group has met numerous times with Iranian officials but has yet to achieve any significant progress.

In late September, the group instructed EU foreign policy chief Catherine Ashton to reach out to Iran’s top nuclear negotiator, Saeed Jalili, to organize another meeting. No date had been set for the possible resumption of talks.