U.S. President Donald Trump says he would agree to meet Iranian President Hassan Rohani if "the circumstances were correct or right."
Tensions between Iran and the United States have ramped up since Washington last year withdrew from a landmark 2015 nuclear deal between Tehran and world powers and reimposed crippling sanctions on the Iranian economy.
Five other signatories, including France, Britain, and Germany, remain committed to the accord under which Tehran agreed to rein in its nuclear activities in return for an easing of sanctions. Iran, however, has begun reducing some of its commitments under the agreement.
Trump, speaking at the Group of Seven (G7) summit in the French seaside resort of Biarritz on August 26, said, "We are looking for no nuclear weapons, no ballistic missiles, and a longer period of time. Very simple."
The three-day G7 summit saw a dramatic shift of focus on August 25, when Iranian Foreign Minister Mohammad Javad Zarif made a brief and unannounced visit to discuss the diplomatic deadlock over Tehran's nuclear program.
Trump said he believed it was realistic he could meet his Iranian counterpart within weeks, following a series of diplomatic initiatives by French President Emmanuel Macron, who earlier voiced hope that "in coming weeks, based on these talks, we can manage to make happen a summit between President Rohani and President Trump."
Asked by reporters if he thought the timeline proposed by French President Emmanuel Macron was realistic, Trump said: "It does," adding he thought Rohani would also be in favor.
"I think he's going to want to meet. I think Iran wants to get this situation straightened out," Trump said.
"I really believe Iran can be a great nation but they can't have nuclear weapons," he added.
Trump warned that if Iran behaves in an aggressive way they "will be met with really violent force."
He also rejected the idea of giving Iran compensation for sanctions imposed by Washington since it pulled out of the 2015 deal.
"No, we are not paying. We don't pay," Trump said, but added that Iran could obtain credit.
"They may need some money to get them over a very rough patch, and if they do need money, and it would be secured by oil -- which to me is great security, and they have a lot of oil -- but it is secured by oil, so we are really talking about a letter of credit. It would be from numerous countries, numerous countries," he said.
Trump earlier on August 26 said there had been "great unity" among G7 leaders over Iran, with a common goal to ensure the country does not acquire nuclear weapons.
He denied that the United States wanted regime change in Iran.
"I'm looking at a really good Iran, really strong. We’re not looking for regime change. You’ve seen how that works over the last 20 years. That hasn't been too good," Trump said as he and other leaders were wrapping up talks.
"Iran really has a chance to really build themselves up and be a really great nation," Trump said, adding: "They have to stop terrorism."
German Chancellor Angela Merkel said that the G7 had made a "big step forward" on Iran.
“There is an atmosphere here in which talks are welcomed, in which talks between the Europeans and Iran and particularly France and Iran are welcomed -- this is happening in coordination with the United States of America, and that is already a lot," she said.
On August 26, Zarif was in Beijing for talks with Chinese Foreign Minister Wang Yi.
China has been a close economic partner for Iran and is among the signatories to the 2015 nuclear deal.
Iran's foreign minister said that after his trip to China he would head to Japan and Malaysia.
In announcing the U.S. pullout from the nuclear deal in 2017, Trump said the terms were not tough enough to prevent Iran from developing nuclear weapons and did not address Iran's missile program or Tehran's support for militants in the region.
Iran has denied it supports insurgent activity and said its nuclear program was strictly for civilian energy purposes.