The Iranian foreign minister denied that any agreement had been reached between Iran and the US on holding one-on-one negotiations over its nuclear programme.

Salehi was speaking on Sunday at a news conference along with visiting Central African Foreign Minister, Antoine Gambi.

"We are not responsible for reacting to everything that is published. We don't have anything like negotiating with the US. We don't have anything in this regard for the time being, but we have been negotiating in that regard with P5+1, and within the framework of P5+1, America is also present."

The White House said it is prepared to talk one-on-one with Iran to find a diplomatic settlement to the impasse over Tehran's reported pursuit of nuclear weapons, but there's no agreement now to meet.

US National Security Council spokesman Tommy Vietor said on Saturday that President Barack Obama has made clear that he will prevent Iran from getting a nuclear weapon and will do whatever is necessary to block that from happening. Vietor said Iran must come in line with its obligations, or else faced increased pressure.

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

Commenting on the explosion in the Lebanese capital Beirut on Friday, Salehi blamed Israel for the explosion, saying they committed the crime to divert public opinion from its failure to foil Hezbollah infiltration into its airspace.

Salehi said Israel "in order to divert public opinion in the region and focus it on other things, has committed such a crime that has left a considerable number of Lebanese citizens killed and many others wounded. In my opinion this is a great sedition and I think they came out with this sedition to further complicate the situation in the region."