"His state of health is improving," presidential spokeswoman Saida Garrach told Tunisian public radio.

"He had a meeting with the defence minister at around 7:45 am, and they exchanged information on the situation in the country," she added.

The spokeswoman gave assurances that president should be released from hospital "soon", without providing further details.

On Thursday, the presidency said Essebsi "was taken seriously ill and transferred to the military hospital in Tunis".

His adviser Firas Guefrech said initially that the president's condition was "critical" before tweeting that he was "stable" and denying rumours that he had died.

Essebsi had already been hospitalised last week, and the latest health scare raised fears a prolonged absence could lead to a period of uncertainty.

Under the constitution, a constitutional court can appoint the country's parliament speaker, currently 85-year-old Mohammed Ennaceur, as interim president in the event of such an absence.

It can also temporarily delegate power to Prime Minister Youssef Chahed.

But eight years after the revolution, political parties have not yet reached an agreement to establish a constitutional court.