Speaking from his refuge in the Gorongosa mountain range, Afonso Dhlakama said he was "very happy" about the agreement signed on Sunday after more than 70 rounds of negotiations.
Dhlakama said he had ordered Renamo to immediately cease hostilities all over the country, including in the central Sofala district, where the group had carried out attacks and ambushes along the south-north highway.
Dhlakama urged President Armando Guebuza to do the same and warned that a failure to do so could jeopardize the peace deal.
The agreement set aside some of the most sensitive disagreements, such as Renamo's demand for joint command of the army. They are due to be dealt with soon, while international observers will prepare to monitor Renamo's disarmament process.
Dhlakama said a meeting was planned between him and Guebuza, though the time and place had not yet been decided.
Renamo is the former rebel movement that signed a peace deal with the ruling Frelimo party in 1992, ending a long, bloody civil war that followed the departure of colonial power Portugal from the southern African country.
It is now the largest opposition party, with 51 members in the 250-seat parliament.
Since March 2012, Renamo has staged mainly highway attacks. The conflict has displaced people and disrupted the Mozambican economy.