In an interview on Tuesday with Britain's Financial Times newspaper, British Foreign Secretary Jack Straw said it was crucial Iraq's draft constitution was ready by a mid-August deadline to pave the way for a troop withdrawal.
"The more certainty you have on that (the constitution), the more you can have a programme for the draw-down of troops which is important for the Iraqis," he said.
"Because - unlike in Afghanistan - although we are part of the security solution there, we are also part of the problem."
The Iraqi panel drawing up the constitution has come under intense US pressure to submit a draft on time.
The Iraqi government and its US backers see the constitution as a key part of any democratic process and hope it can help defuse the two-year-old uprising and allow US and British troops to withdraw sooner.
Separately, Polish Prime Minister Marek Belka said post-war nation-building efforts in Iraq had "failed totally", but expressed hope that the country's different religious groups could work together to build an independent nation.
Straw has admitted UK troop
presence is part of the problem
Belka, speaking at a panel discussion on nation-building at an international forum in Sweden, said on Monday the United States and its allies made a mistake by basing its post-war plan for Iraq on the same model used for Germany after the second world war.
"It failed totally," Belka said. "Many mistakes, major mistakes, have been committed." But there are reasons to be optimistic about Iraq, he added, including the success of recent elections.
"The political process is moving on," he said, adding that elected officials in Iraq are "doing what should be done".
However, the key for creating an independent nation in Iraq is to "reconcile the divergent interests" of the country's three major groups, the Shia, Sunni Arabs and Kurds, Belka said.
Staunch US ally
"There is much more of an Iraqi identity [among the groups] than you might think," he said. "They all think in terms of Iraq."
"[The post-war plan for Iraq] failed totally... Many mistakes, major mistakes, have been committed"
Polish prime minister
Poland, a staunch US ally, participated in the invasion of Iraq and has commanded a multinational force there since September 2003.
Since then, the Polish-led force's size has shrunk from 9500 to 4000 troops.
Belka was speaking at a round-table discussion that was part of the Tallberg Forum 2005, where more than 400 politicians, business leaders, artists and scholars discussed how people from different cultures and religions can best live together.