The European powers, known as the E3, "are in contact with Iran to schedule further talks for the coming week", the source said, following warnings from the trio that international sanctions against Iran could be reactivated if Tehran does not resume negotiations.

Iran's Tasnim news agency also reported that Tehran had agreed to hold talks with the three European countries, citing an unnamed source.

Consultations are ongoing regarding a date and location for the talks, the report said.

Iranian Foreign Minister Abbas Araghchi held a call Friday with his British, French and German counterparts and European Union foreign policy chief Kaja Kallas.

During the call, the Europeans warned that if Iran did not return to talks soon, they would activate a so-called "snapback" mechanism to reimpose sanctions lifted in a 2015 deal to curb Tehran's nuclear output.

Iran and the United States had held several rounds of nuclear negotiations through Omani mediators before Israel launched its 12-day war against Iran on June 13.

However, US President Donald Trump's decision to join Israel in striking Iranian nuclear facilities effectively ended the talks.

"Iran must never be allowed to acquire a nuclear weapon. That is why Germany, France and the United Kingdom are continuing to work intensively in the E3 format to find a sustainable and verifiable diplomatic solution to the Iranian nuclear programme," the German source said.

Iran denies it is pursuing nuclear weapons.

The 2015 deal between Iran and world powers, called the Joint Comprehensive Plan of Action (JCPOA), placed significant restrictions on Tehran's nuclear programme in exchange for sanctions relief.

But the hard-won deal began to unravel in 2018, during Trump's first presidency, when the United States walked away from it and reimposed sanctions on Iran.

"If no solution is reached over the summer, snapback remains an option for the E3," the German source said.