Technical Talks on Iran Nuclear Row Open in Istanbul

Technical experts from Iran and major world powers gathered Tuesday in Istanbul for closed door talks on Tehran's disputed nuclear program, a European diplomat said.

The meeting between nuclear physics experts from Iran and the major powers known as P5+1 -- the five permanent members of the U.N. Security Council and Germany -- takes place without the participation of diplomats, the source said.

This technical level resumption of talks over Iran's controversial nuclear aims was set after the last summit between the P5+1 and Iran in June in Moscow.

The downgraded round of talks comes at a time when Iran hardened the tone of its criticism against the Western countries for dragging out the negotiations.

Iran is insisting it has a "right" to uranium enrichment under the nuclear Non-Proliferation Treaty, which should be recognized by the P5+1. It also wants Western sanctions punishing its economy to be eased.

The world powers instead are pushing for an immediate end to Iran's enriching uranium to 20 percent purity -- just a technical step short of the 90 percent needed to make nuclear bombs -- and to ship out its existing 20-percent stock and close a fortified underground enrichment facility in Fordo.