The White House is condemning the alleged bombing of civilians by the Sudanese government in two southern states, calling it unjustified and unacceptable.

A White House spokesman Thursday said such attacks as those in Blue Nile and Southern Kordorfan violate international law and worsen the ongoing crisis in Sudan.

He said the fighting and Sudan's refusal to grant access to relief groups means southern Sudan is just weeks from what the White House calls a Stage 4 humanitarian crisis — one step away from a famine.

The Sudanese government denies targeting civilians as it pursues rebels along the border with newly independent South Sudan. Many of those rebels sided with the South during a decades-long civil war that ended in 2005.

Fighting broke out last year between Sudan and rebels in South Kordofan and Blue Nile. In recent months Sudan has carried air and ground attacks in Southern Kordofan, displacing tens of thousands of people and forcing many to flee into neighboring South Sudan.