**US Secretary of State Hillary Clinton is due to arrive in Switzerland at the start of a five-day tour of Europe.**In Zurich, she will witness the signing of a historic pact between Turkey and Armenia to normalise relations after a century of hostility.
She is to meet British Prime Minister Gordon Brown on Sunday in London, where the Afghan war is expected to be high on the agenda.
On Monday, she will address the Northern Ireland assembly in Belfast.
Visiting Russia for the first time as chief US diplomat, Mrs Clinton will hold talks on Iran’s disputed nuclear programme with Russian President Dmitry Medvedev in Moscow on Tuesday.
She is expected to press the Russian leader for a strong commitment for tough new sanctions on Tehran.
Officials say she will also raise other issues, including arms control, missile defence, and cooperation to convince North Korea to abandon nuclear weapons.
Mrs Clinton returns to Washington late on Wednesday, after visiting Russia’s mainly Muslim city of Kazan.
But her first order of business is to attend the signing ceremony in Zurich of the Turkish-Armenian normalisation pact.
The US State Department said Mrs Clinton had been closely engaged with the parties to move the process along and was attending the ceremony to show Washington’s support for the historic agreement, says the BBC’s Kim Ghattas.