US:The White House has sought to put a brave face on Britain's decision to start withdrawing troops from Iraq but Democrats say it as a rejection of President George Bush's policy in Iraq.
Vice-president Dick Cheney claimed the British decision to cut numbers by 1,600 in the coming months was good news and a sign of progress in Iraq.
"I look at it and what I see is an affirmation of the fact that there are parts of Iraq where things are going pretty well," he told ABC News.
However Democratic senator Edward Kennedy said the British decision highlighted Mr Bush's growing isolation.
"No matter how the White House tries to spin it, the British government has decided to split with President Bush and begin to move their troops out of Iraq . . .
"Eighteen other countries have already withdrawn or dramatically reduced their troop presence in Iraq," Mr Kennedy said. "A majority of the American people voted last November for a changed policy in Iraq. A majority of the House and the Senate and numerous generals have rejected the administration's policy in Iraq, and now our country's strongest ally has rejected it.
A spokesman for House speaker Nancy Pelosi criticised the administration for sending more troops to Iraq at a time when other countries were preparing to withdraw.
"Today's announcement raises the question: why are thousands of additional American troops being sent to Iraq at the same time that British troops are planning to leave?"
Announcing the troop withdrawal to the House of Commons, British prime minister Tony Blair came under sustained opposition fire.
The Conservatives and Liberal Democrats welcomed news that the British deployment in Basra will be cut from 7,100 to "roughly" 5,500 over the next few months, with the possibility of a further fall in troop numbers there to 5,000 by late summer.
However Tory leader David Cameron pressed Mr Blair to at least accept "the principle" now of the need for an inquiry into the conduct of the Iraq war and the decisions made.
At the same time Lib Dem leader Sir Menzies Campbell urged the prime minister to "ignore the voices in Washington arguing and perhaps even preparing for military action against Iran".
Mr Blair was in characteristically defiant form, defending his foreign policy on Iraq and the whole of the Middle East, while insisting yesterday's announcement of security handovers to the Iraqi authorities would not mean any "diminution" in Britain's combat capability.
In a statement to MPs he said the British military presence in Iraq would continue into 2008 and "for as long as we are wanted and have a job to do."
Amid suspicions that decisions are now being dictated by the timetable for Mr Blair's departure and the upcoming Labour leadership election, there was relief for Downing Street with US secretary of state Condoleezza Rice's assurance that "the coalition remains intact" and that these decisions were dictated by conditions on the ground.
Declaring the successful conclusion of "Operation Sinbad", Mr Blair said the situation in Basra was very different from other parts of Iraq, in particular Baghdad. He said the problems facing Basra were still "formidable" and that the situation there remained "difficult and sometimes dangerous".
The plans had been agreed with Iraqi prime minister Nouri Maliki. These would see British troops remaining in Iraq hand over all bases except for Basra air base and Basra palace to local authorities, with the bulk of British troops then withdrawing to the air base over the next few months.
From there they would provide support to the Iraqi security forces and have responsibility for training home-grown troops, securing the Iraq/Iran border, securing supply routes and conducting operations against extremists.
Mr Blair told the House: "It is important to show, and show particularly the Iraqi people, that we do not desire our forces to remain any longer than they are needed but whilst they are needed, we will be at their side."
Mr Blair said the claim by extremists to be fighting for the liberation of their country was "a palpable lie". He said: "They know perfectly well that if they stop their terror, agree to let the UN democratic process work and allow the natural talent and wealth of the country to emerge, we would be able to leave."