Sudan's ruling National Congress Party (NCP) on Sunday demanded the South Sudanese government to stop supporting the rebels who are fighting the system in Khartoum and not to provide shelter for the rebel leaders.

"Juba government's support for the rebels cripples the implementation of the joint cooperation agreements with South Sudan," Yasir Yousif, spokesman of the NCP political sector, told reporters on Sunday.

"Immediately after the recent attacks in North and South Kordofan, the South Sudanese government has been notified with the available information to Sudan that the south has provided support for this operation," he added.

He did not rule out the possibility that Juba's support for the rebels would be discussed in a summit between the Sudanese President Omar al-Bashir and Kiir during an expected visit for the latter to Khartoum.

Yousif further reiterated that Khartoum would not negotiate with the Sudan People's Liberation Movement (SPLM)/northern sector which is fighting the Sudanese government at the South Kordofan and Blue Nile areas until after militarily defeating it and liberate all the Sudanese territories.

On Saturday the Sudanese national intelligence and security service disclosed involvement of South Sudan in the recent attack by the rebel revolutionary front against North and South Kordofan States.

Local Sudanese media organs reported director of the information department at the national intelligence and security service to have said that "Juba is involved in supporting the rebels who attacked Um Rawaba and Abu Karshula areas and its support has not ceased even after the signing of the matrix of the cooperation deal between the two countries."

The South Kordofan and Blue Nile states have been witnessing armed clashes between the Sudanese army and the SPLM/northern sector since 2011 after South Sudan's independence.

Two weeks ago the revolutionary front, which brings together the SPLM/northern sector, the Darfur rebel Justice and Equality Movement (JEM), the Sudan Liberation Army ( SLA)/Abdul-Wahid Mohamed Nur faction and the SLA/Minni Minawi faction, attacked Um Rawaba and Alla-Kareem areas in South Kordofan State.

Khartoum's accusations of Juba came following remarkable improvement in the relations between Sudan and South Sudan after the two signed on March 8 in Addis Ababa, Ethiopia, a matrix deal to implement the security arrangements agreement and the cooperation agreement which tackled security, border, oil, trade and other issues.