Canadian Prime Minister Stephen Harper speaks with United States President Barack Obama as they wait for a session to begin on the second day of meetings at the G20 Summit in Cannes, Friday November 4, 2011. Harper heads to the White House on Wednesday to unveil a long-awaited border security agreement with U.S. President Barack Obama, but the visit comes at a particularly tense moment in Canada-U.S. relations as TransCanada's Keystone XL pipeline saga rages on. THE CANADIAN PRESS/Adrian Wyld