EU foreign policy chief Catherine Ashton has announced that in a telephone conversation regarding nuclear talks, Iran has agreed to resume negotiations with world powers.

Ashton confirmed that on Thursday she spoke with Saeed Jalili, the Secretary of Iran’s National Security Council and the country’s chief nuclear negotiator, to discuss how to explore “diplomatic ways to resolve international concerns about Iran’s nuclear program."

Ashton said: “I impressed the need for Iran now to address the issues we have raised in order to build confidence."

Last week Ashton and Jalili’s deputies met in Istanbul for hours of talks, concluding that the negotiations had to continue at higher levels.

The world powers have urged Iran to stop enriching uranium to the 20-percent level and transfer its stockpile of enriched uranium to another country under the supervision of the six major powers involved in the negotiations.

Iran says that as a signatory to the NPT, it has a right to exploit nuclear power for peaceful purposes, which includes enriching uranium to produce fuel for its nuclear reactors.

The U.S. and EU have imposed severe sanctions on Iran’s energy and financial sector to make Iran more flexible in the negotiations, but so far Iran has remained defiant.