Barack Obama has said he is willing to open dialogue with Iran on its nuclear programme, after concillitory signs from the country's new President Hassan Rouhani.
However, the US President said on Tuesday that Iran would have to demonstrate its own seriousness by agreeing not to "weaponise nuclear power".
"There is an opportunity here for diplomacy," Obama said in an interview with the Spanish language television network Telemundo.
"I hope the Iranians take advantage of it. There are indications that Rouhani, the new president, is somebody who is looking to open dialogue with the West and with the United States, in a way that we haven't seen in the past. And so we should test it."
The interview came as the US confirmed that Israel's Prime Minister Benjamin Netanyahu would visit the White House on September 30 to consult Obama on Iran's nuclear challenge, Syria and Palestinian peace talks.
Netanyahu said he was keen to discuss Iran's nuclear programme with Obama, ahead of expected new talks between Tehran and world powers.
"I intend to focus on the issue of stopping Iran's nuclear programme," a written statement from the Israeli leader's office said.
Israel has accused the Islamic Republic of trying to develop and build nuclear weapons. Iran denies the allegations.
Netanyahu said Israel would demand that Iran halt all uranium enrichment, remove all enriched uranium from its territory, close its underground nuclear facility in Qom and stop building a plutonium reactor.
"Only a combination of these four steps will constitute an actual stopping of the nuclear program, and until all four of these measures are achieved, the pressure on Iran must be increased and not relaxed, and certainly not eased,"
However, Obama's interview was the latest indication that the president would like to jump from the crisis over Syria's chemical weapons to a new search for a diplomatic deal to ensure Iran does not develop a nuclear weapon.
Obama revealed last weekend that he and Rouhani had exchanged letters about the US-Iran standoff.
Both leaders will be at the UN General Assembly in New York next week, although White House officials say they are no plans for them to meet.
Hopes for a new round of nuclear talks between Iran and world powers expected to resume soon were boosted earlier on Tuesday by cryptic remarks by the Ayatollah Ali Khamenei, Iran's Supreme Leader.
Khamenei said that sometimes flexibility was necessary in diplomacy.
On September 11, Rouhani said he had the tacit support of Khamenei for "flexibility" in nuclear talks.
Rouhani has said he wants to allay Western concerns but that he will not renounce Iran's goal of an independent civil nuclear programme.
Washington and its allies say Iran's nuclear programme is designed to produce weapons and is unacceptable. Obama has refused to rule out US military action against Iran if diplomacy fails.
Iran insists that its nuclear ambitions are directed towards civilian energy generation.
Obama ran for president in 2008 in part by vowing to open a dialogue with Iran. But there has been no breakthrough and sanctions by Washington and the UN to weaken Iran's economy have gradually been increased to try to pressure Tehran to give up a nuclear programme that it denies is aimed at building a weapon.
Since the surprise election in June of Rouhani, a moderate, officials from both countries have made increasing hints that they are open to direct talks to seek an end to the decade-long nuclear dispute.