The constitutional decree stated that the declaration of the cease-fire came "to prepare the atmosphere for achieving peace and security in all parts of Sudan."
The decree instructed all concerned authorities to immediately implement the cease-fire as of the date of its issuance.
The constitutional decree came hours after the Sudan People's Liberation Movement (SPLM)/Northern sector, led by Abdelaziz al-Hilu, announced suspension of negotiations with Sudan government until all the movement's demands are responded to, including declaration of cease-fire and release of the movement's detainees.
South Sudan's capital Juba has been hosting peace talks between Sudanese government and armed groups from Darfur, South Kordofan and Blue Nile regions.
Sudan's Justice and Equality Movement, the Sudan Liberation Movement, and the SPLM/Northern sector are participating in the talks with the government.