US President Barack Obama(C) and British Prime Minister David Cameron greet US Vice President Joe Biden(L), along with Jill Biden, US Treasury Secretary Timothy Geithner and others during official welcoming ceremonies March 14, 2012 at the White House in Washington, DC as Samantha Cameron(2ndR) and First Lady Michelle Obama(R) follow. AFP PHOTO/Karen BLEIER (Photo credit should read KAREN BLEIER/AFP/Getty Images)