Morales did not mention a date, or say whether he would run for re-election.
Morales, Bolivia's first indigenous leader, took office for a five-year term in January 2006, saying he would increase state control of natural resources and spread wealth to the impoverished Indian majority who form his power base.
He also made good on his promise to call an assembly to rework the country's constitution.
Assembly delegates began meeting in August, in the southern city of Sucre, and have up to a year to produce a new legal framework for Bolivia, South America's poorest country.
Assembly members are expected to discuss a total overhauling of all branches of government, including whether to turn the bicameral congress into a single house legislature.
Morales, a former llama herder and coca leaf grower who grew up in poverty, nationalised Bolivia's energy industry last year and has repeatedly pledged to implement reforms to the country's dilapidated mining sector.