BAGHDAD (Reuters) - Vice President Joe Biden arrived in Baghdad on Tuesday to visit U.S. troops nearing completion of their withdrawal from Iraq by year-end.

Biden's visit spotlights a key pledge fulfillment by President Barack Obama as he campaigns for re-election in 2012, winding down an unpopular war at a time when most Americans are preoccupied with the weak economy at home.

(Reporting by Alister Bull, editing by Mary Milliken)