UK Prime Minister Tony Blair and US President George Bush are to hold talks next week about the Middle East.
It is Mr Blair's second visit to the White House in two months
Mr Blair will visit the White House on Saturday 29 July for the meeting.
The packed agenda includes finding "lasting peace" in the Middle East, Iraq, Iran, Afghanistan, fighting in Darfur and free and fair trade.
News of the summit comes after the archbishop of Canterbury criticised the US and UK for failing to call for a ceasefire between Israel and Lebanon.
Announcing the talks, the White House said: "The United States has no closer ally and partner than the United Kingdom, and the president appreciates the prime minister's leadership and vision."
It is the prime minister's second Washington visit in less than two months - he discussed Iraq with Mr Bush at the end of May.
Last week, Mr Blair was overheard telling Mr Bush he was prepared to travel the Middle East to "prepare the ground" for a visit by US Secretary of State Condoleezza Rice.
But the president did not appear to be keen to take up the offer.
Mr Blair has also backed calls for a multinational force to go to southern Lebanon to help stop the violence there.
Mr Bush is waiting for a UN mission to the region to report on whether a force would be useful.
Officials say the summit has been expected for some time and is not a response to the continuing fighting in Lebanon.
But the crisis is likely to be high on the agenda.
On Friday, Israel called up reserves and urged people to leave southern Lebanon, a possible prelude to a ground offensive.
The fighting began when Hezbollah militants in Lebanon killed and captured Israeli soldiers and launched rocket attacks on Israel.
The Archbishop of Canterbury, Rowan Williams, said the UK and US should change their minds on their refusal to call for an immediate ceasefire.
"We really have to ask whether some Western governments are catching up with the consciences of their own people", he told BBC Radio 4.
He said calls for an immediate ceasefire might not work but the violence was not going to stop without them.
"The major players in this at the moment who are not supporting a ceasefire - our own government and the United States government - maybe perhaps have to reckon with a rising level of public despair and dismay at the spiral continuing," he said.
"And I hope very much that they will bring their influence to bear in moving towards a ceasefire."
UN Secretary General Kofi Annan has called on Israel and Hezbollah to bring hostilities in Lebanon to a swift end.
The US and UK have condemned Lebanon but not Israel, saying only that there should be a "proportionate" response to Hezbollah's attacks.
British Foreign Secretary Margaret Beckett told BBC News: "Our use of language is determined by what we think is right, what we believe, and what we think will be effective."
She criticised people who said the US could stop the violence immediately if it wanted.
"Actually the people who have the easiest path that they can take, the people who have the answer to a stop of violence, now this minute, in their hands, are the people who hold those kidnapped Israeli soldiers."