"A low-key meeting was organized by Qatar in Doha last week between delegations from the government of the Democratic Republic of Congo (DRCongo) and the AFC/M23 movement, marking their first direct meeting in a long time," the source said, quoted by French news agency AFP.
"The meeting was positive, reinforcing trust between the two parties, which led to the withdrawal of M23 forces from the strategic town of Walikale, in a gesture of goodwill and a show of support for the ongoing dialogue," he added.
According to the source, "new talks are now expected to take place in Doha, still under Qatari mediation, in order to maintain momentum and explore constructive solutions to end the conflict."
In late January, the Rwandan-backed M23 launched a major offensive and within a few weeks took control of the two main cities in eastern DR Congo, Goma and Bukavu.
Since then, calls from the international community for the withdrawal of the armed group and Rwandan troops have gone unheeded.
Diplomatic attempts to resolve the crisis, including mediation led by Angola, all failed until Qatar's surprise intervention last month, which brought together the Presidents of the DR Congo, Félix Tshisekedi, and Rwanda, Paul Kagame, in Doha.
The two heads of state, at the invitation of Emir Tamim ben Hamad Al-Thani, spoke of a ceasefire, on the same day that an attempt at a direct meeting between delegations from the Government of the DR Congo and the M23 in Luanda failed.
The next day, M23 captured a new town, Walikale, in an area rich in gold and tin.
On Thursday, local and security sources said the M23 had withdrawn from Walikale, as Donald Trump's special adviser for Africa, Massad Boulos, visited Kinshasa.