British Prime Minister Tony Blair paid a farewell visit Wednesday to President George W. Bush, a final opportunity for two close allies to showcase their unity on the unpopular war in Iraq and to try to hammer out differences on climate change and trade. Blair arrived Wednesday at Andrews Air Force base outside Washington, ahead of a private dinner with Bush. After spending the night at the White House, Blair will discuss issues with Bush Thursday, and then hold a joint news conference. "The World Trade Organization talks will be high on the agenda because we are approaching crunch point," Blair's official spokesman said on condition of anonymity, in line with government policy. "The run-up to the G-8 will be important, particularly on climate change."