Former Congolese president Joseph Kabila will return to the central African nation to help find a solution to the crisis in the war-ravaged east, where Rwanda-backed M23 rebels have seized swathes of territory, he told Reuters late on Tuesday.

The M23 rebels' lightning offensive since January in Democratic Republic of Congo's mineral-rich east has killed thousands and forced hundreds of thousands more from their homes, while stoking fears of a wider regional conflict.

Congolese government and M23 sources told Reuters this week that peace talks between Congo and Rwanda planned for April 9 in Doha were delayed, with no new date scheduled for them to take place. Rwanda denies backing the rebels.

"I have resolved to return home without delay to contribute to the search for a solution," said Kabila, who was in office from 2001 to 2019 and left the country in 2023, living in South Africa and spending time in other African countries since then.

His return would be contentious in Congo.

The son of President Laurent Kabila, he came to power after his father's assassination and refused to stand down when his final term officially expired in 2016, leading to deadly protests.

Kabila's opponents accused him of delaying elections in order to organise a referendum to let himself stand for a third term. He finally agreed in 2018 to step down following an election that December.

President Felix Tshisekedi and Kabila formed an awkward power-sharing deal following Congo's disputed 2018 election. But Tshisekedi later accused his predecessor of blocking reforms.

Tshisekedi, who took office in 2019, has recently accused Kabila of backing the rebels.

Their relationship soured and as M23 marched on eastern Congo's second-largest city, Bukavu, in February, Tshisekedi publicly accused Kabila of sponsoring the insurgency.

Kabila, meanwhile, has been reaching out to opposition politicians and civil society members to discuss the country's political future amid criticism of Tshisekedi's response to M23's campaign.

In March, three officials from Kabila's party were called in for questioning by a military prosecutor over comments one of them had made a month earlier. Their lawyer said no charges were laid against them.

"I have decided to begin with the eastern region, where there is danger at hand," Kabila said, outlining his plans in a written message that said this followed consultations with national and foreign powerbrokers and other actors in the conflict.