Fighters loyal to ex-rebel chief Frederic Bintsamou - seen as having disbanded after a 2003 peace deal - rose up again in April last year in protest at the re-election of President Denis Sassou Nguesso.
The fighting in the southern Pool region affected at least 138,000 people and halted district elections in July.
It also cut off crucial transport routes between the capital Brazzaville and the main oil port - worsening an already dire economic situation for the country affected by plunging crude prices.
"There's a time to make war and a time to make peace. And the time to make peace has arrived," Interior Minister Raymond Zephirin Mboulou said Wednesday.
"The people of Pool don't deserve what has been happening there."
A new ceasefire deal was signed last month in Pool's regional capital Kinkala between government officials and Jean-Gustave Ntondo, a representative of Bintsamou.
Government and rebel representatives have now formed a joint commission to thrash out the deal's implementation.
President Sassou Nguesso, 73, has led Congo for over 30 years.
The former paratrooper served as president from 1979 to 1992, and then returned to power in 1997 following a civil war with Pastor Ntumi's so-called Ninja rebels.
Sassou Nguesso won two successive terms in elections in 2002 and 2009, both of which were disputed by opposition parties.