Rice: Success İn Iraq 'not a Sure Thing'

The road for the US in Iraq has been "harder, longer, and more difficult than I personally imagined," Rice said adding that the country has seen a "hopeful but fragile turn of events."

She made the remarks at the State Department to salute General David Petraeus and US Ambassador to Iraq Ryan Crocker on Monday. Petraeus was promoted to head the US Central Command in the Middle East. His former deputy, Lieutenant-General Raymond Odierno, took his place in Iraq.

Meanwhile, on Sunday, Britain's top military commander in Afghanistan Brigadier Mark Carleton-Smith told The Sunday Times that the public should "lower their expectations" about how the conflict will end in Afghanistan.

In its bid to give legal basis to its military and political presence in the Iraq, the US is seeking to sign a security deal - Status of Forces Agreement (SOFA) - with the oil-rich country. A UN mandate that governs the presence of U.S. forces in Iraq expires at the end of the year.

Washington and Baghdad are still at loggerheads over key issues in the controversial US-proposed security pact including, the number of bases the US will retain in Iraq, immunity from prosecution of US personnel and the provision of a troop withdrawal timetable.