Iran's supreme leader accused the United States on Wednesday of war-mongering and of turning the Gulf into an arms depot, hitting back at U.S. accusations that the Islamic state was moving toward a military dictatorship.

The comments by Ayatollah Ali Khamenei were the latest sign of growing tensions between Tehran and Washington, which are embroiled in a long-running and escalating row over Iranian nuclear work the West suspects is aimed at making bombs.

The United States is leading a push for the U.N. Security Council to impose a fourth round of sanctions on Iran, which says its nuclear program is solely to generate electricity so it can export more of its oil and gas.

Last month, U.S. officials said the United States had expanded land- and sea-based missile defense systems in and around the Gulf -- a waterway crucial for global oil supplies -- to counter what it sees as Iran's growing missile threat.

U.S. Secretary of State Hillary Clinton said on Monday the United States believed Iran's Revolutionary Guards were driving the country toward military dictatorship and should be targeted in any new U.N. sanctions.

In an apparent reference to Clinton's visit to the Middle East earlier this week, Khamenei said the Americans had dispatched their agent to the region to accuse Iran's Islamic system of government.

But no one believes these lies because they know that America is the real war-mongering state. They have turned the Persian Gulf into an arms depot, Khamenei said.

They invaded Afghanistan and Iraq and are now accusing the Islamic Republic. Everybody knows that the Islamic Republic is for peace and brotherhood among all Islamic states in the world, Khamenei said, state television reported.

PUNCH IN THE MOUTH

Iran faces growing Western calls for a new round of targeted U.N. sanctions against it after President Mahmoud Ahmadinejad last week ordered the start of higher-grade uranium production.

During her three-day visit to Qatar and Saudi Arabia, Clinton denied the United States planned to attack Iran and said Washington wanted dialogue with Tehran but could not stand idly by while Iran pursued a suspected nuclear weapons program.

The West accuses Iran of covertly trying to build nuclear bombs. Iran, the world's fifth-largest crude oil exporter, says its nuclear facilities are part of a peaceful energy program and it would retaliate for any attack on them.

Khamenei, Iran's top authority, said the Iranian people had punched its enemies in the mouth by turning out in large numbers to rallies last week marking the 31st anniversary of the 1979 Islamic revolution.

On Thursday, Iranian state television said tens of millions of people rallied to support the revolution across the country of 70 million, which is facing its worst domestic crisis in three decades after a disputed presidential election last June.

An opposition website said security forces fired teargas at opposition supporters staging a Tehran counter-rally on the February 11 anniversary of the revolution that toppled the shah.

Khamenei, who like other Iranian leaders accused the West of stoking post-election unrest and meddling in Iran's internal affairs, accused arrogant powers of opposing the Islamic Republic because of its call for justice in the world.

We should mourn the day when the global imperialism praises us, he said.

(Editing by Peter Millership)

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