Barham Salih, in London for talks with Tony Blair, the prime minister, made clear his anxiety about the change in tone from London and Washington, where senior figures are questioning whether the current strategy in Iraq is viable.
Salih told BBC radio on Monday: "I'm obviously concerned about the debate both in the US and Europe, I have to say."
"There is too much of a pessimistic tone to this debate - even I would say in certain circles a defeatist tone.
"We need to be realist but not defeatist. We need to understand that there is a need of utmost urgency to deal with many of the problems of Iraq, but we must not give in to panic," he said.
The number of US military deaths in Iraq in October has reached 85, making it the most deadly month for Americans this year and raising pressure on George Bush, the US president, before congressional elections next month in which Republicans could lose majorities in both houses.
US military officials in Iraq have admitted that a two-month plan to secure Baghdad has failed.
"We need to keep our nerve. We need to get Iraq back on its feet. We need to establish greater stability"
British foreign secretary
In Britain, General Richard Dannatt, the army chief, sparked a political storm this month by saying British troops should withdraw from Iraq soon as their presence was worsening security there and in the wider world.
Salih said the current situation in Iraq could not go on.
"Especially the last month has been exceptionally tough and difficult, but really failure is not an option," he said.
"I do believe there is no option for the international community to cut and run ... the fate of Iraq is vital to the future of the Middle East and world order."
British officials gave a similar message before their meetings with Salih.
Margaret Beckett, the foreign secretary, said: "We need to keep our nerve. We need to get Iraq back on its feet. We need to establish greater stability."