President Barack Obama and German Chancellor Angela Merkel arrive for their joint news conference in the Rose Garden of the White House in Washington, Friday, May 2, 2014. Obama and Merkel are putting on a display of trans-Atlantic unity against an assertive Russia, even as sanctions imposed by Western allies seem to be doing little to change Russian President Vladimir Putin's reasoning on Ukraine. (AP Photo/Charles Dharapak)

Obama threatens more Russia sanctions

Projecting unity on Ukraine, President Barack Obama and German Chancellor Angela Merkel are threatening broader sanctions against Russia.