Iran's Supreme Leader Ayatollah Ali Khamenei said on Friday the Islamic Republic would not yield to international pressure to abandon its nuclear course, threatening retaliation for sanctions aimed at Iran's oil exports.

"Threatening Iran and attacking Iran will harm America....  Sanctions will not have any impact on our determination to continue our nuclear course.... In response to threats of oil embargo and war, we have our own threats to impose at the right time," Khamenei told worshippers in a speech broadcast live on state television.

The official Iranian news agency IRNA quoted Iran's Supreme Leader as saying that war threats would "disfavor the US itself; the war would be ten times against interests of the US itself,” said the Supreme Leader.

"I have no fear of saying that we will back and help any nation or group that wants to confront and fight against the Zionist regime [Israel]."

On Thursday, British Deputy Prime Minister Nick Clegg said in an interview that he was concerned that "certain" countries" would take the Iran nuclear issue into their own hands, refusing to say whether or not Britain would "participate" the military conflict that could ensure as a result from such a move.

Clegg was quoted as telling The House Magazine, a weekly British political journal, that he feared Israel could carry out a pre-emptive strike on Iran amid suspicion in the West that Tehran is secretly developing nuclear weapons.

Tensions have been heightened over Iran’s intentions, leading UN Secretary-General Ban Ki-moon on Wednesday to warn Israel that the standoff over Tehran’s nuclear program must be resolved peacefully.

Asked if he feared Israel could launch an attack against Iran, Clegg — leader of the Liberal Democrats, the junior member of Britain’s coalition government, acknowledged he had concerns.

“Of course I worry that there will be a military conflict and that certain countries might seek to take matters into their own hands,” Clegg was quoted as saying.

He said Britain had been attempting to demonstrate “that there are very tough things we can do which are not military steps in order to place pressure on Iran.”
Last week, the European Union agreed to tougher sanctions, including an embargo on Iranian oil imports.

However, Clegg said he would not speculate on whether “Britain would participate” if the standoff eventually led to a military response.