"Have you not tested the Iranian nation? We will continue on our path with power and will not allow the oppressors to deny this nation's right," Khamenei was quoted by the state radio as saying to world powers.

"Threats will not force the Iranian nation to back down," it quoted him as saying on a visit to the southern Fars province.

Khamenei's comments came after the five permanent members of the United Nations Security Council plus Germany Friday agreed on a new proposal of incentives to Iran in a bid to resolve the standoff over its nuclear program.

Although no details of the new proposal have been made available yet, Russia said that world powers were asking Tehran only to suspend uranium enrichment during a period of talks.

Iran has defied U.N. Security Council resolutions that it halt uranium enrichment, which can be used both to generate nuclear energy and make the explosive core of a nuclear bomb.

Although Khamenei made no reference to the new package, his comments are the latest sign from Tehran that it has no intention of giving ground on the key sticking point of enrichment.

The West fears Iran could use uranium enrichment to make atomic weapons but Iran denies this is its aim, insisting it has a right to enrichment to make nuclear fuel as a signatory to the nuclear Nonproliferation Treaty.

Iranian Foreign Minister Manouchehr Mottaki Saturday again rejected a suspension of enrichment, describing such a move as Iran's "forbidden zone."

"In a meeting with the British foreign secretary (at a conference earlier this month in Kuwait) I said: You know what the forbidden zone is, then be careful not to enter the forbidden zone," he said.

Following Friday's talks in London, British Foreign Secretary David Miliband said the powers had "reviewed and updated" an offer made to Iran in June 2006, which included economic, security and technological rewards.