Mustafa Usman Ismail said he will meet al-Marghani, the head of the National Democratic Alliance (NDA), on Sunday to discuss a resumption of negotiations between the government and the NDA in the Egyptian capital Cairo.
Khartoum and the Cairo-based opposition umbrella group were due to sign a final accord on 12 February covering political, constitutional and legislative issues, but the deal was never signed.
The accord is aimed at lifting the state of emergency in place since 1989 and setting up a joint commission to look at how to integrate the NDA into politics.
The NDA is a coalition of northern organisations and is seen as a rival to the Al-Umma party - Sudan's legal opposition - and the outlawed Popular Congress.
Meanwhile, Ismail said that during his trip to Saudi Arabia he would also deliver a message from Sudan's President Umar al-Bashir to Saudi Crown Prince Abd Allah bin Abd al-Aziz concerning the countries' bilateral relations.
Ismail praised the bilateral ties, describing them as "excellent in the economic, political and negotiations security fields".
He noted that Saudi Arabia "is one of the few countries that effectively contributes to offering humanitarian assistance to Darfur, particularly with regards to helping the displaced persons there."