Tony Blair hopes a "signal of intent" on the Middle East will emerge from his meeting with President George Bush.
Tony Blair and George Bush are holding talks over two days
With the issue set to be top of the agenda in Washington this week, the prime minister is eager to see movement from the re-elected president.
Mr Blair's spokesman said it was widely accepted momentum had been lost, partly because of the US election campaign.
He said: "The priority is to restore that momentum - it is important to get a signal of intent."
Mr Blair's spokesman added: "But work has been going on in the background ... so we are not starting with a blank page. A clear signal of intent will have a lot of depth behind it."
Other issues on the agenda are likely to include American relations with Europe and the UK and climate change.
Meanwhile, the prime minister was urged by UK industry chief Digby Jones to use his meeting with the president to persuade him to open up the US to global trade.
If the US continues to indulge in protectionism, the Confederation of British Industry chief said, the poorer nations of the world will get poorer.
The CBI chief said Mr Blair should say to the US leader: "President Bush, you think you are the home of the brave and the land of the free, well you may be brave but you ain't free."
He told BBC Radio 4's Today programme: "They are one of the most protectionist nations in the Western World.
"We have to get the biggest economy on Earth to understand its responsibility to the world, which in turn will help jobs in America."
Mr Blair was "ahead of the game", Mr Jones said, adding: "I would like to think President Bush can learn from Tony Blair on this."
Liberal Democrat leader Charles Kennedy on Sunday said he hoped Mr Blair could persuade the US president to break the deadlock over Middle East peace.
And the Conservatives have said the prime minister must use the talks to demand Britain has a greater say in decision-making in Iraq.
'Changing our climate'
Former Tory environment minister John Gummer urged the prime minister to push for action on climate change.
He said Mr Blair had never brought home to Mr Bush that he must take action on the issue in the return for the support that he and others had given.
The US was changing the world's climate, he said, adding that the biggest challenge for Mr Bush in winning world support was to show that he understands the concern and is going to do something about it.
Many of Mr Blair's Labour colleagues are no fans of President Bush
The prime minister has already made clear the agenda he will be flying to Washington with.
Speaking last week, he said the war on terror must involve bringing democracy to Iraq, a renewed commitment to Middle East peace and the alleviation of poverty in Africa.
Mr Blair also urged other European leaders to rebuild bridges with the US after the damage to transatlantic relations caused by the Iraq war.
George Bush senior, the former president, said Mr Blair's calls for the Middle East to be a key US priority had been "heard loud and clear" in Washington.
He told BBC Breakfast with Frost: "There is a real opportunity. People forget that this President is the first
President to call for a Palestinian state."
Republican Senator of Oregon Gordon Smith suggested the possibility of a new Palestinian leadership, in the light of Yasser Arafat's failing health, would give the opportunity for a "new chapter" to open.
A White House statement said: "The UK stands as one of America's closest allies, and Tony Blair as one of America's greatest friends."
Culture Secretary Tessa Jowell has said Mr Bush's re-election had caused much disappointment within Labour but added the prime minister should put his "very strong alliance" with the president to "its best