Video: George Clooney warns US Congress of South Sudan disaster "It is a campaign of murder and fear and displacement and starvation," Clooney, a longtime activist on the Sudan issue, told the Senate Foreign Relations Committee. Let's use the techniques we've learned from chasing terrorists and find and freeze the offshore bank accounts of these war criminals. They are not buying these weapons with Sudanese pounds. Let's work with the international community to toughen the sanctions, make Khartoum a very lonely place," he said. Violence has flared along the Sudan-South Sudan border since South Sudan seceded last year, and some experts worry the conflict could grow. The two sides remain locked in disputes over issues including the position of their border, control of the disputed Abyei territory, and what transit fees South Sudan pays its northern neighbor to export oil from Port Sudan. Tensions have been further exacerbated since South Sudan shut down all its oil fields in January in protest of Khartoum's seizure of crude it said was to make up for unpaid fees. Clooney also plans to meet with US President Barack Obama and Secretary of State Hillary Clinton to discuss the humanitarian crisis.