Washington, April 11, 2010 : President Barack Obama will hold a series of bilateral meetings one day ahead of a historic nuclear security summit in Washington.

Secretary of State Hillary Rodham Clinton says the two-day gathering — which starts Monday — will be the largest assembly of world leaders hosted by a U.S. president since the 1945 San Francisco conference that founded the United Nations.

Obama will move to set the tone Sunday by meeting separately with the leaders of India and Pakistan — two nuclear armed foes that have avoided atomic war. He’ll also meet with leaders of South Africa and Kazakhstan. Both countries voluntarily gave up nuclearweapons programs.