US President Barack Obama scolded both sides of Sri Lanka's quarter-century-old civil war on Wednesday.

He demanded that the Sri Lankan government stop shelling hospitals and that Tamil Tiger rebels stop using civilians as human shields.

Before leaving the White House for a trip to the state of Arizona, Obama told reporters that the situation on the south Asian island country could develop from a humanitarian crisis into a full-blown catastrophe.

He strongly urged both sides to take steps to alleviate suffering. The US president also asked the Sri Lankan government to give United Nations and Red Cross staff access to the 190-thousand displaced civilians.

Barack Obama, US President, said, "The United States stands ready to work with the international community to support the people of Sri Lanka in this time of suffering. I don't believe that we can delay. Now is the time for all of us to work together to avert further humanitarian suffering."

(CCTV May 14, 2009)