"We want to hold negotiations, but we have new conditions, which I will disclose next week," he said.

Western powers suspect Iran of attempting to build nuclear weapons and the UN Security Council approved on June 9 the fourth round of economic sanctions against Iran over its nuclear program, including tougher financial controls and an expanded arms embargo.

Tehran maintains that its nuclear program is aimed at generating peaceful civilian energy.

Ahmadinejad said he regretted the UN Security Council's decision to impose a new round of sanctions against Iran and called the move "counterproductive."

He also stressed that Iran will make no concessions to any country.

Last Wednesday the Iranian parliament passed a bill directing the government to scale down its cooperation with the International Atomic Energy Agency (IAEA) following the imposition of the sanctions.

Iran's nuclear chief Ali Akbar Salehi announced on Wednesday that the country had produced 17 kilograms of 20%-enriched uranium and could produce as much as it needed.

He said Tehran was not going to turn its entire uranium stockpile into 20%-enriched fuel but that it reserved "the right to enrich fuel to any level needed."