The UN chief called for more talks on Iran's atomic program, saying new sanctions against Tehran have not shut the door to a diplomatic resolution of its nuclear standoff with the West, Reuters reported.

"Even with the Security Council's resolution adopted on other sanctions, the door is still open for a negotiated settlement," Secretary-General Ban Ki-moon said.

Ban was responding to a question about Iranian President Mahmoud Ahmadinejad's announcement that Iran is ready to resume talks on its nuclear program but wants to delay them for several weeks to punish the West for imposing new sanctions.

Ahmadinejad said Iran would be prepared to return to talks only by the second half of the Muslim festival of Ramadan - in late August. "It's a punishment to teach them a lesson to know how to have a dialogue with nations," he said.

Ban said he discussed Iran with top European Union officials on the sidelines of the summit of leaders of the Group of 20 club of big developed and developing nations in Canada. He called for Iran and the five permanent U.N. Security Council members and Germany to resume negotiations.

"I will continue to urge the leaders of the world, the concerned parties to continue their negotiations for an eventual resolution of this issue," he said.

Earlier this month the Security Council passed a fourth round of sanctions against Tehran over a nuclear program that countries around the world increasingly suspect is aimed at producing arms. Tehran rejects the allegations and says its atomic ambitions are limited to generating electricity.

The new U.N. sanctions against Iran, which received the backing of Tehran's traditional supporters Russia and China, were followed by new rounds of tougher EU and U.S. measures.