Sudan's president is threatening war with the newly independent South Sudan.
President Omar al-Bashir, who is wanted by the International Criminal Court for war crimes in Darfur, boasted he will "liberate" South Sudan from the "insects" that rule it.
Recent weeks have seen increasing violence near the oil-rich town of Helig, which both sides claim as its own. Bashir said the fighting has "revived the spirit of jihad" in Sudan.
World leaders fear the fragile 2005 peace agreement, which led to the creation of South Sudan, could come apart.
Bashir's Islamic government waged war against Christians and Black Africans in the south for 20 years, with the death toll estimated as high as 2 million.
The South legally declared its independence in July. Since then, Bashir's forces have carried out attacks against civilians in Kordofan State, which borders the two countries.
Thousands of refugees have sought safety in South Sudan.