Pushpa Kamal Dahal -- better known as Prachanda -- issued a statement Thursday on the seventh anniversary of the Maoist insurgency.
He said the rebels take the peace process very seriously and will play a responsible role.
But he said his fighters are ready to resume fighting at any moment if there are signs of deception by the government.
Hundreds of pro-Maoist students marched in Kathmandu Thursday to mark the anniversary of the rebellion. Riot police stood by and no violence was reported.
The Nepalese government and the Maoists declared a ceasefire last month in the seven-year rebellion to overthrow the country's constitutional monarchy. The fighting has killed more than seven-thousand people.
The government agreed last month to cancel arrest warrants for several Maoist leaders and stop calling the rebels "terrorists."
Both sides agreed to hold peace talks, but it is unclear when negotiations will start.
Nepalese officials say careful preparations are still under way, but the rebels have already named their negotiating team.
Three rounds of peace talks and a ceasefire failed in 2001.