Sudan's government conditionally accepted on Tuesday an invitation to attend US-sponsored peace talks in Geneva, raising hopes that the talks could advance efforts to end a 15-month-old war. 

The government is aligned with the army in its war with the paramilitary Rapid Support Forces (RSF). The army has shunned recent bids to restart ceasefire or peace negotiations, with Islamists who hold sway in its ranks calling for a military victory. 

The Geneva talks would be the first major effort in months to get the army and the RSF to sit together. The RSF accepted the US invitation soon after they were proposed last week. 

"The government said (in its reply to the invitation) that it was the party most concerned with saving the lives and dignity of the Sudanese people, and so it will cooperate with any entity that aims to do so," the Sudanese foreign ministry said in a statement. 

The war has caused the world's largest humanitarian crisis with a fifth of the population displaced and famine likely across the country. Previous talks convened by the United States and Saudi Arabia in Jeddah broke up without agreement. 

The RSF, which clashed with the army over plans to integrate their forces last year, has taken control of eight of Sudan's 18 state capitals, including the capital Khartoum, and is expanding further into the southeast of the country. 

"The government made clear that any negotiations before ... full withdrawal and an end to expansion (by the RSF) will not be acceptable to the Sudanese people," the statement said. However, it also requested meetings with US officials to discuss the agenda for the talks. 

US special envoy Tom Perriello told reporters on Monday both sides had been receptive to offers of meetings in advance of formal talks. A planned meeting in the army's de facto capital Port Sudan was cancelled but would hopefully be rescheduled, he said.