Sudanese leaders have postponed to next week the signing of an agreement to resume a short-lived democratic transition, an official said on Saturday, amid continued disagreement between military factions.

A coup in October 2021 led by army chief Abdel Fattah al-Burhan had derailed the transition to civilian-led rule that began following the 2019 ouster of Islamist general Omar al-Bashir.

Security reforms are a key point of contention in negotiations held over the past weeks, building on a preliminary accord reached in December to install a civilian government.

The signing ceremony intially planned for Saturday is now expected on Thursday instead to finalise "technical issues linked to the reform of the security forces", said Khaled Omar Youssef, a civilian official arrested during Burhan's coup who now serves as spokesman for the talks.

The December deal, reached after near-weekly protests since the 2021 coup, calls for the military's exit from politics once a civilian government is installed.

The proposed reforms include the integration into the regular army of the powerful paramilitary Rapid Support Forces (RSF), led by Burhan's deputy Mohamed Hamdan Daglo.

The two men have been at loggerheads over the timetable for the RSF's integration and analysts have pointed to a deepening rift between them, although they appeared side by side in Khartoum last week to plead for a successful integration.

Created in 2013, the RSF emerged from the Janjaweed militia that Bashir unleashed a decade earlier in the western region of Darfur against non-Arab rebels. The militia has since been accused by human rights groups of having committed war crimes.

The worsening state of Sudan's economy has put pressure on all sides to reach a deal.

The country has faced a chronic shortage of hard currency since the 2011 secession of South Sudan that has been exacerbated by foreign aid cuts since the coup.

The crunch came just as Russia's invasion of Ukraine last year sent world food and fuel prices soaring beyond the means of most Sudanese.