The New York Times, quoting unnamed US administration officials, had said on Saturday that secret exchanges between US and Iranian officials had yielded agreement "in principle" to hold one-on-one talks.
"We don't have any discussions or negotiations with America," Iranian Foreign Minister Ali Akbar Salehi told a news conference. "The [nuclear] talks are ongoing with the P5+1 group of nations. Other than that, we have no discussions with the United States."
The United States has been working with the P5+1 to pressure Iran on its nuclear program, but with few results. The United States and other Western powers allege that the program is aimed at developing nuclear weapons, but Tehran says it is purely peaceful.
White house denies
"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."
Salehi said on Sunday it was planned that Iran would hold talks with the P5+1, "probably in late November," according to the Iranian Students' News Agency (ISNA).
P5+1: 'No Date'
But a spokesman for EU foreign policy chief Catherine Ashton, who is coordinating the efforts of the P5+1, said that "we hope that we will pick up discussions soon, but there is no date at the moment".
The P5+1 has held a series of inconclusive meetings with Iranian officials in the past year. While Western officials say there is still time to negotiate, they also have been ratcheting up sanctions, which are contributing to mounting economic problems in Iran.
The New York Times said Iran had insisted that its direct talks with Washington should not begin until after the US election on Nov. 6, which will determine whether Obama serves a second term or is succeeded by Romney.
The report looked likely to fan campaign debate over foreign policy, where Romney has been accusing Obama of being an ineffective leader who has left his country vulnerable.
He has also accused Obama of failing to give adequate support to Israel, which sees the prospect of a nuclear-armed Iran as a threat to its existence and has tried in vain to persuade Obama to spell out at what point the United States would use force to prevent Iran acquiring nuclear weapons.
Iran has repeatedly denied Israel's right to exist.
"This issue showed that the Zionists [Israelis] and Americans must know that no place is safe for them anymore," Mohsen Kazemini was quoted as saying by Fars.
Separately, the Guards' top commander, Mohammad Ali Jafari, said on Sunday he saw no chance of a military strike on Iran, ISNA reported.
Jafari's comments were in contrast to a statement last month in which he said he expected Israel eventually to go beyond threats and attack Iran.