Obama has called on the Island nation to stop 'indiscriminate shelling' on the civilians and has urged the Tiger rebels to surrender without which there would be a humanitarian 'catastrophe'.
"Without urgent action, this humanitarian crisis could turn into a catastrophe," Obama said.
"So I urge the Tamil Tigers to lay down their arms and let civilians go. Their forced recruitment of civilians and their use of civilians as human shields is deplorable," the president added.
With the United Nations estimating about 50,00 civilians trapped in the war zone, he called on the Lankan government to take 'steps to alleviate this humanitarian crisis'.
Making a reference to an earlier report of the rebels accusing the government of shelling a hospital tending to the wounded, he said "First, the government should stop the indiscriminate shelling that has taken hundreds of innocent lives, including (in) several hospitals."