Leaders in Washington for nuclear security summit

India's Prime Minister Manmohan Singh waits to deplane at Andrews Air Force Base, Maryland, April 10, 2010, as he arrives in advance of his participation in the nuclear security summit in Washington called by US President Barack Obama. [Photo/Agencies]  

U.S. President Barack Obama (R) meets with India's Prime Minister Manmohan Singh at Blair House in Washington D.C. April 11, 2010. Singh is in town for this week's nuclear security summit. [Photo/Agencies]