The White House says President Bush will meet Thursday in Washington with Salva Kiir, a vice president in the national Sudanese government and the president of semi-autonomous southern Sudan.

A statement Tuesday said the two leaders will discuss implementation of the Comprehensive Peace Agreement that ended Sudan's north-south civil war in 2005.

The agreement has appeared increasingly shaky, especially since former southern rebels withdrew their ministers from the national government in Khartoum last month.

The Sudan People's Liberation Movement has accused Khartoum of blocking implementation of the peace deal. The former rebels are demanding withdrawal of northern troops and more control over the oil-producing Abiya region.

The White House says Mr. Bush and Mr. Kiir will also discuss efforts to bring peace to Sudan's troubled Darfur region. Peace talks in Libya last month made little progress as the chief Darfur rebel groups refused to attend.