Tehran, Iran ? Iran vowed Sunday to expand its uranium enrichment, defying a U.N. Security Council deadline for it to suspend its nuclear activities by the end of the month or face the threat of political and economic sanctions.

Top nuclear negotiator Ali Larijani’s statement was Tehran’s first warning since the resolution passed that it could step up its atomic program. It suggested Iran is feeling emboldened in its main confrontation with the West, over its nuclear program, as Europe and the United States scramble to deal with the escalating violence between Israel and Lebanon-based Hezbollah militants.

“We will expand nuclear activities where required. It includes all nuclear technology including the string of centrifuges,” Larijani said, referring to the equipment Iran uses to enrich uranium, which can be used as fuel for a nuclear reactor or fissile material for an atomic warhead.

Iran also gave its Hezbollah allies a green light to keep fighting in Lebanon, saying that the United States – which put forward a cease-fire plan with France Saturday – can’t be a mediator in the crisis because of its support for Israel.

The U.S. has “no right to enter the crisis as a mediator” in the Mideast fighting, hard-line Iranian President Mahmoud Ahmadinejad said in a telephone conversation with his top ally, Syrian President Bashar Assad, according to a report on Ahmadinejad’s official Web site.

“They (the U.S.) think that through the U.N and the Security Council they can achieve the goals which they could not achieve militarily,” he said.

The outbreak of fighting between Israel and Hezbollah – triggered by a July 12 militant raid into Israel that ended with the capture of two Israeli soldiers – has moved the focus of the Security Council’s attention from its efforts to halt Iran’s uranium enrichment program.

Many in the U.S., Europe, the Arab world and Israel accuse Iran of fueling the warfare in Lebanon through Hezbollah in a bid to show its regional strength.