The talks will be a follow-up to the last round of negotiations held in Almaty between Iran and the P5+1 group of world powers -- Russia, China, France, Britain, and the US plus Germany.

Jalili, who is also the secretary of Iran Supreme National Security Council (SNSC), is to attend a press conference on Thursday to brief media on the outcome of his talks with Ashton.

Iran and the P5+1 have held several rounds of talks mainly over the Iranian nuclear energy program. Their latest rounds of talks were held in Kazakh city of Almaty on April 5-6 and February 26-27.

During April meeting, Iran presented the P5+1 with the details of its proposal “to launch a new round of cooperation” between the two sides, SNSC Undersecretary Ali Baqeri said on April 5.

The United States, Israel, and some of their allies have repeatedly accused Iran of pursuing non-civilian objectives in its nuclear energy program.

Using this false allegation as pretext, the US and the EU have imposed several rounds of illegal unilateral sanctions against the Islamic Republic.

Tehran rejects the allegation over its nuclear energy activities, maintaining that as a committed signatory to the Non-Proliferation Treaty and a member of the International Atomic Energy Agency, it has the right to use nuclear technology for peaceful purposes.