The southern African country has been fighting a prolonged Islamist insurgency that has cast doubt over the development of large gas deposits discovered in its restive north.

"The extension of the service time... and professionalisation (of the armed forces) constitute essential factors to forge and mould troops with standards that are up to the challenges of National security," National Defence Minister Cristovao Chume told parliament.

All Mozambicans have to register with the armed forces upon turning 18, although not all are called up to serve in the military, depending on factors including health, studies, professional career and government needs.

The law is still subject to possible amendments and will need to be signed by President Filipe Nyusi before coming into force.

Mozambique has set high hopes on vast natural gas deposits -- the largest found south of the Sahara -- that were discovered in the northern Cabo Delgado province in 2010.

If all the deposits are tapped, Mozambique could become one of the world's 10 biggest gas exporters, according to estimates.

But an insurgency waged by militants linked to the Islamic State group in the region has stalled progress.

More than 4,700 people have been killed and almost a million have been forced to flee their homes since 2017.

The government has regained control over much of the region since the deployment of thousands of troops from a regional force and Rwanda, following an attack on the city of Palma in 2021.

But sporadic raids and incursions from the jihadists continue.