A senior Iranian Foreign Ministry official said ahead of the conversation between Supreme National Security Council head Saeed Jalili and Javier Solana that Tehran would not yield to international demands and back down on its right to pursue civilian nuclear technology.
Iran failed to give its reply Saturday - an informal deadline set by the six nations involved in the long-running nuclear talks - to proposals designed to persuade Tehran to suspend uranium enrichment, a process that can be used in nuclear weapons production.
The United States said Iran would now inevitably face tougher sanctions. Tehran brushed aside the warning.
"During a conversation on Monday afternoon, the parties agreed to continue discussions launched in Geneva," the Supreme National Security Council said in a statement after Monday's talks. "The sides agreed to contact each other in the next few days."
Solana's press service did not give details of the talks but said he would brief the so-called Iran Six - the five permanent UN Security Council members and Germany - of Iran's position.
At talks in Geneva on July 19, the six nations put forward a package of trade and nuclear technology incentives to Tehran, demanding a response within two weeks.
Iran's Islamic Revolution Guards Corps Commander Mohammad Ali Jafari reiterated a threat in comments quoted by Fars news agency on Monday to block the Strait of Hormuz, through which about 40% of global oil shipments pass, in the event of aggression against the country.
The U.S. and Israel have refused to rule out military action against Iran, the world's fourth largest oil producer, if diplomacy fails to end the dispute.
Iran has recently conducted a series of missile test launches in the strait, which is located at the southern end of the Persian Gulf.
