Tony Blair will fly to the United States today for talks with President Bush and Kofi Annan after weeks of increasing violence in Iraq.

The Prime Minister, who is in Bermuda on holiday, is due to meet Mr Annan, UN Secretary General, tonight in New York before going on to talks with Mr Bush in Washington tomorrow.

The spiralling violence in Iraq promises to top the agenda for the talks, but Ariel Sharon's plan for an Israeli withdrawal from the Gaza Strip is also likely to figure heavily.

Mr Annan gave a lukewarm response to the bilateral agreement between the Israeli Prime Minister and Mr Bush, but the Prime Minister has backed the deal, which could see Israel retain large parts of the West Bank in any Middle East peace plan.

Mr Blair and Mr Bush are facing increasing pressure over the military strategy in Iraq, with coalition troops fighting two separate uprisings across the country. Eight US soldiers have been killed in the last 24 hours.

Military commanders desperately need to restore order across the country. But critics have argued that their use of overwhelming firepower is serving only to unite the people of Iraq against the occupying forces. Even the UN yesterday criticised the coalition's tactics.

But Downing Street has insisted there was no split between the two coalition partners and stressed Mr Blair backed the US strategy and approach.

Sir Christopher Meyer, former British ambassador in Washington, said the two leaders would be putting on a united front.

He told the BBC: "If you think we are going to see within the next two or three days any public divisions between President Bush and Prime Minister Blair I think that would be wrong.

"A characteristic of the British-American relationship is one of extremely robust exchanges in private with a tendency to show almost complete unity in public.

"Above all what Tony Blair will want is agreement, very clear agreement, on the steps that Britain and American will need to take in Iraq with their partners to take us through 30 June, through to the end of the year – which of course covers the election itself in the US - and into 2005.

"And of course the Middle East – Arab-Israel – will be a factor in that as well as Iraq itself."

Mr Blair's visit comes after the UN's special envoy to Iraq, Lakhdar Brahimi, yesterday spoke of his confidence that the hand-over of power would take place on the June 30 deadline.

Both Mr Blair and Mr Bush are determined to stick to that date, despite demands at home from the Conservatives that it should not be set in stone.

Mr Bush have warning yesterday that the people of Iraq would question the intentions of the coalition if it did not stick to the deadline.

The talks are of particular importance to Mr Bush. His close relationship with Mr Blair, who is hugely popular in the US, is a significant asset in the run-up to the presidential election.