Iran will not talk to the United States until all sanctions imposed on Tehran are lifted, President Hassan Rouhani said on Tuesday, a day after President Donald Trump said he would meet his Iranian counterpart to try to end a nuclear standoff.

Mr Trump said on Monday he would meet Iran's president under the right circumstances to end a confrontation over Tehran's 2015 nuclear deal with six powers and that talks were underway to see how countries could open credit lines to keep Iran's economy afloat.

Mr Rouhani said Iran was always ready to hold talks "but first the U.S. should act by lifting all illegal, unjust and unfair sanctions imposed on Iran."

"Without the U.S.'s withdrawal from sanctions, we will not witness any positive development," Mr Rouhani said in a televised speech on Tuesday, adding that Washington "holds the key" as to what happens next.

"If someone intends to make it as just a photo op with Rouhani, that is not possible," he said.

Earlier on Monday, Mr Rouhani expressed readiness to negotiate a way out of the crisis following America's pullout from the nuclear deal.

Tensions high as Trump approves new Iran sanctions: In pictures Show all 17 1 /17 Tensions high as Trump approves new Iran sanctions: In pictures Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, their surface-to-air missile is seen as it shoots down a US surveillance drone EPA Tensions high as Trump approves new Iran sanctions: In pictures This photo shows US RQ-4A Global Hawk unmanned surveillance drone. A drone of this model was shot down by Iran on Thursday 21 June AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures An oil tanker is on fire after it was subject to a suspected attacked at the Gulf of Oman on June 13. The US has blamed Iran for the attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures US President Trump holds up a signed executive order to increase sanctions on Iran on 24 June AP Tensions high as Trump approves new Iran sanctions: In pictures Iranian President Rouhani stated in a televised address that the White House is "afflicted by mental retardation" following the increase in sanctions on 25 June EPA Tensions high as Trump approves new Iran sanctions: In pictures An Iranian navy boat tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures A screenshot from a video released by the US Department of Defense that the US claims to show Iranian removing an unexploded limpet mine form the hull of the Japan-owned ship that was attacked in the Gulf of Oman on June 13 Getty Tensions high as Trump approves new Iran sanctions: In pictures An item reportedly found on the Japan-owned oil tanker that was attacked on June 13 in the Gulf of Oman AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures A handout photograph from the US Department of Defense shows a composite material that the US claim was left behind on the hull of the Japan-owned oil tanker following the removal of an unexploded limpet mine Getty Tensions high as Trump approves new Iran sanctions: In pictures A view from the cabin of an Iranian navy boat as it tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack EPA Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The picture suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The pictures suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack EPA

"If I knew that going to a meeting and visiting a person would help my country's development and resolve the problems of the people, I would not miss it," he had said.

"Even if the odds of success are not 90% but are 20% or 10%, we must move ahead with it. We should not miss opportunities."

Mr Rouhani's U-turn can be seen as a result of pressure from hard-liners in the Iranian establishment who oppose taking a softer tone towards the West.

Speaking at a G7 summit in the French resort of Biarritz, Mr Trump ruled out lifting economic sanctions to compensate for losses suffered by Iran.

European parties to the deal have struggled to calm the deepening confrontation between Iran and the United States since Mr Trump pulled Washington out of the 2015 nuclear deal with world powers and reimposed sanctions on the Iranian economy.

Iran has scaled back its commitments under the pact in retaliation to US sanctions.