Bamako is on edge after the brazen attack claimed by an extremist group formed by notorious Algerian militant Moktar Belmoktar.
A statement from Belmoktar’s group, Al-Mourabitounes (The Sentinels), and carried by Al-Jazeera also described co-ordination with al Qaida’s “Sahara Emirate”.
President Ibrahim Boubacar Keita announced a 10-day nationwide state of emergency beginning at midnight.
He said a three-day period of national mourning was due to begin on Monday, with flags flying at half-mast.
Mr Keita had been attending a security summit in Chad on Friday but returned to Mali and convened an emergency cabinet meeting.
Northern Mali has been unstable since it fell to Tuareg separatists and Islamic extremists following a military coup in 2012.
Despite a French-led military intervention in 2013 that drove the extremists from cities and towns, attacks have continued and extended farther south this year, including an assault on a Bamako restaurant popular with foreigners in March.
Even before the attack ended on Friday, some officials said it highlighted the need for tighter security measures and stricter surveillance.
“Today we have an emergency. These terrorists are a global threat that we need to attack globally,” said politician Amadou Thiam, a vice president of Mali’s parliament.
“Our government needs to introduce stricter identification and information systems so that we can track everybody.”
The heavily armed assailants on Friday seized dozens of hostages at the hotel popular with foreigners, sparking a seven-hour siege by Malian troops backed by US and French special forces.