WASHINGTON: US Secretary of State Hillary Clinton left for Europe and Russia to pursue Washington's drive to curb Iran's nuclear ambitions and rally more support behind its war in Afghanistan.

In a frenetic five-day, six-city tour, Clinton is scheduled to arrive inZurich on Saturday to watch Armenia and Turkey sign what aides call a "historic" Swiss-brokered deal to normalize their relations.

She then travels to London, Dublin, Belfast, Moscow and Russia's mainly Muslim city of Kazan.

Visiting Ireland and Russia for the first time as chief US diplomat, she will aim to bolster Northern Ireland's reconciliation process and push for a new US-Russia nuclear arms cut deal by a December 5 deadline, aides said.

But since September, Iran, Afghanistan and Pakistan have taken up much of the agenda in Washington and the UN General Assembly inNew York, and aides said the countries will be high on the list for Clinton's talks in Zurich, London and Moscow.

Washington has expressed some hope of eventually getting Tehran to halt its suspect uranium enrichment program since Iran met last week in Geneva with the permanent five veto-wielding members of the UN Security Council -- Britain, China, France, Russia and the United States -- plus Germany, also known as the P5-plus-1 group.

Ahead of the trip Clinton sounded upbeat about her talks next week in Moscow with Foreign Minister Sergei Lavrov and President Dmitry Medvedev, who have raised hopes Russia might consider tougher sanctions against Iran if it fails to cooperate.

In Zurich, Clinton will hold informal talks on Iran with both French Foreign Minister Bernard Kouchner andEuropean Union Foreign Policy Chief Javier Solana, a senior State Department official said on condition of anonymity.

Clinton "will talk with senior UK officials on a wide range of bilateral and transatlantic issues, including Iran, Afghanistan and Pakistan," said Philip Gordon, assistant secretary of state for European and Eurasian affairs.

Britain has 9,000 troops in Afghanistan, the second largest deployment after the United States.