President Bush hosts outgoing British Prime Minister Tony Blair at a farewell summit today.
Mr Blair's last scheduled visit to Washington before stepping down next month underscores the price he has paid for embracing Mr Bush, backing the US-led 2003 invasion of Iraq and maintaining his support.
While the war has damaged both leaders' standing, it is Mr Blair who will leave office in mid-term, under pressure from within his own Labour Party to step aside before the next general election expected in 2009.
Mr Blair will hold talks and a joint news conference with the president today.
The prime minister is expected to give priority to several issues, including narrowing US-European differences on global warming before next month's G8 summit of industrialised countries in Germany, trying to advance stalled world trade talks and alleviating poverty in Africa.
The two are expected to show a unified front on the Iraq war as they have for more than four years of combat in Iraq, where Britain provided the largest non-US contingent of troops for the invasion.
Mr Bush will be looking for further assurances that Mr Blair's presumed successor, finance minister Gordon Brown, will not lessen Britain's resolve in Iraq. Mr Brown has accepted that mistakes were made in Iraq but has ruled out an immediate pullout.