The main rebel group in eastern Democratic Republic of Congo, the M23, has walked away from peace talks with the government, saying it will not return unless the authorities adhere to a previous ceasefire deal.
Fighting between the two sides escalated in January, when the M23 captured large parts of the mineral-rich east, including the regional capital Goma.
In Qatar last month, the rebels and the government signed a ceasefire agreement, intended as a step towards a permanent peace deal.
But on Monday, as negotiations were set to resume, the M23 said its representatives were not present in Qatar.
M23 spokesperson Lawrence Kanyuka told the BBC's Great Lakes service that the Congolese government "doesn't want peace".
He accused the authorities of not respecting the provisions contained in the ceasefire deal, but DR Congo's military denies this charge.
Kanyuka alleged that government forces had continued to attack rebel positions, despite the agreement stating that both sides must refrain from assaults.
However, the Congolese armed forces accused the M23 of launching attacks almost daily in the North Kivu and South Kivu provinces.
The Qatar peace deal was supposed to be signed by Monday.
On Sunday, an unnamed official from Qatar told the AFP news agency that a draft agreement had been shared with DR Congo and the M23.
The agreement runs alongside a peace deal between DR Congo and Rwanda, which was brokered by the US in June.
DR Congo, the UN and numerous Western powers have accused Rwanda of backing the M23.
Despite participating in the Washington peace talks, Rwanda has long denied the allegations against it.
The Washington peace deal, hailed by President Donald Trump as a "glorious triumph", could grant the US access to DR Congo's vast mineral wealth.
However, it is the latest in a long line of failed peace deals in the region.
During the ongoing conflict, thousands of people have been killed and hundreds of thousands of civilians forced from their homes, the UN says.
