WASHINGTON - The White House on Saturday denied a press report saying the United States and Iran had agreed for the first time to have one-on-one talks over the latter's controversial nuclear program.

"It's not true that the United States and Iran have agreed to one-on-one talks or any meeting after the American elections," Tommy Vietor, spokesman of the National Security Council, said in a statement.

"We continue to work with the P5+1 on a diplomatic solution and have said from the outset that we would be prepared to meet bilaterally," he added, referring to Britain, China, France, Russia and the United States, the five UN Security Council permanent members, and Germany.

The New York Times first broke the news on its website Saturday afternoon, quoting Obama administration officials.

The paper said the agreement was the result of intense and secret exchanges between officials of the two countries, which began almost immediately after President Barack Obama took office in January 2009.

Noticeably, the news came just two weeks before the American voters head to polls to choose a new president between Obama and his Republican rival Mitt Romney, and just two days before the pair are scheduled to have their third and last face-to-face debate mainly on foreign policy issues.

The Romney campaign has launched a scathing attack on Obama's foreign policy record, the president's widely recognized strong suit, despite the Obama campaign's repeated boasting of its strong achievements, including the imposition of crippling sanctions against Iran never seen before.

Romney and his team have accused Obama of being weak on Iran while pressing hard on Israel, Washington's close ally in the region.

The Obama administration has advised Israel against premeditated attacks on the nuclear sites inside Iran on the grounds that the sanctions are biting and there is still "time and space" to seek a peaceful resolution through the two-track approach of pressure and diplomacy.

Obama and his aides have also refused to set a "red line" for military strikes against Iran, as requested by Israeli Prime Minister Benjamin Netanyahu and other top officials, though the president has declared that he would take no options off the table to stop the Islamic republic from obtain nuclear bombs.

The agreement for direct talks "has the potential to help Mr. Obama make the case that he is nearing a diplomatic breakthrough in the decade-long effort by the world's major powers to curb Tehran's nuclear ambitions, but it could pose a risk if Iran is seen as using the prospect of the direct talks to buy time," the New York Times said.

In exchanges with their American counterparts, the Iranian officials "have insisted that the talks wait until after the presidential election," the paper quoted a senior administration official as saying, adding the Iranians want to know with whom they would be negotiating.

Iran has rejected for years one-on-one talks with the United States, a country it has described as the Great Satan, "reflecting what experts say are internal power struggles," the paper said.

Iran insists on the peaceful nature of its nuclear program, while Washington and its Western allies regard it as a cover for developing nuclear weapons.

The six powers, the so-called P5+1, have been negotiating with Iran over terms on ending its uranium enrichment program in the past years, with three rounds in place so far this year.

"The prospect of direct talks is why there has not been another meeting of the major-powers group on Iran," the New York Times quoted a senior American official as saying.

The UN Security Council imposed four rounds of sanctions on Iran between 2006 and 2010 over its refusal to halt its nuclear enrichment program, and the United States and the European Union have imposed and expanded sanctions of their own over the years.

In his statement, Vietor warned Iran of more crippling sanctions over its continuing refusal to "come in line with its obligations".

"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," he added.