Touadera's opponents have already accused him of seeking to extend his rule despite constitutional limits in one of the world's poorest and most unstable countries.
"I have decided... to submit this project for a new constitution to a referendum," the president said in an address to the nation posted on Facebook, with the date set for July 30.
Touadera was elected in 2016 and was returned for a second term in 2020, despite widespread accusations of electoral flaws and an ongoing rebellion against his rule after years of civil war.
In January, he removed the country's top judge, Daniele Darlan, in what critics denounced as a "constitutional coup d'etat" after she opposed presidential decrees aimed at revising the constitution.
Currently a president can serve only two terms.
"There won't be a third term, but the count will be set back to zero, so anyone can seek a new term, including Touadera if he wants," the president's main advisor, Fidele Gouandjika, told AFP after the announcement.
Critics said the president was making a blatant power play.
"This new constitution will be written so that Touadera remains president for life," said Nicolas Tiangaye, a former prime minister and opposition leader.
"What's more, the Constitutional Court is illegitimate since the ouster of Darlan," he said.
Touadera has also drawn fire from critics over the hiring of paramilitaries from the Russian group Wagner in the conflicts between militias that hold sway over large tracts of territory and often clash over access to minerals and other resources.
The last remaining French troops were also forced to leave in December in the face of an increasingly assertive Russian presence, with Paris accusing CAR authorities of being complicit in an anti-French disinformation campaign allegedly fomented by Russia.
France, the former colonial power, had dispatched up to 1,600 troops to help stabilize the country after a coup in 2013 unleashed a civil war along sectarian lines.
Landlocked and mineral-rich but dirt-poor, the CAR has experienced few periods of stability since gaining independence from France in 1960.
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