Sudan on Monday offered to speed up the implementation of security and oil deals with South Sudan after tension flared on their disputed border last week.
But South Sudan said the process is stalled because of Khartoum's insistence on the South "disarming" rebels operating on northern territory.
Concern has grown that the agreements mediated by the African Union (AU) have not gone into effect two months after Sudan's President Omar al-Bashir and his South Sudanese counterpart Salva Kiir hailed them as ending conflict.
The neighbouring states fought along their undemarcated border in March and April.
"President Bashir in a telephone conversation with Salva Kiir agreed to hasten the implementation of the cooperation agreement," the official SUNA news agency said.
The September deals included a demilitarised border buffer zone designed to cut support for insurgencies in Sudan, while allowing a resumption of South Sudanese oil through northern pipelines for export.
In January, South Sudan halted crude production -- which accounts for almost all of its government revenue -- after accusing Khartoum of theft in a long-running dispute over transit fees.
South Sudan became independent last year under a peace deal ending a 23-year civil war.
Khartoum has accused South Sudan of supporting rebels of the Sudan People's Liberation Movement-North (SPLM-N), which has been fighting since last year in Sudan's border states of South Kordofan and Blue Nile.
Analysts believe the charge, despite denials by Juba which in turn accuses Khartoum of supporting rebels on southern territory.
Speaking to South Sudanese governors on Monday, Kiir said that disarming the SPLM-N was an impossible mission for South Sudan because the rebel group operated in a different country.
Sudan's army last Wednesday confirmed it launched an attack in the Samaha area near the South Sudanese border where another group of rebels, from the Darfur region, had set up a compound.
But South Sudan said bombs landed on its territory, killing seven civilians.© ANP/AFP