In a message to the nation, President Roch Marc Christian Kabore said the people of Burkina Faso must unite against terrorism.
He also announced security forces would be stepping up their efforts to thwart future attacks and asked people to comply with new restrictions.
Mr Kabore said: “These truly barbaric criminal acts carried out against innocent people, claimed by the criminal organisation al-Qaeda in the Islamic Maghreb (AQIM) seek to destabilise our country and its republican institutions, and to undermine efforts to build a democratic, quiet, and prosperous nation.”
Three days of national mourning began yesterday, a day after Burkinabe and French forces ended a more than 12-hour siege at the upscale Splendid Hotel in downtown Ouagadougou.
When the gunfire and explosions finally stopped, authorities said 18 were killed in the hotel and 10 were killed at the nearby Cappucino Cafe.
Among the victims were the wife and young daughter of Italian Gaetan Santomano, who owned the cafe.
Government officials say the toll also includes six Canadians, five Burkinabes, two Swiss nationals, two French citizens and one American.
The American — Michael Riddering, 45, of Cooper City, Florida — had been working as a missionary in Burkina Faso since 2011, where he and his wife ran an orphanage that also provided shelter to abused women and widows. He is survived by his four children, two of whom were adopted in Burkina Faso.
Swiss authorities said its two nationals were also in Burkina Faso for humanitarian reasons.
Yesterday, French authorities were back at the scene carrying out a forensic investigation. Special forces from the former coloniser came during the overnight siege from their base in neighbouring Mali to help Burkina Faso’s military put an end to the killings.
Some guests returned to the Splendid Hotel to pick up their luggage and other belongings left behind when guests fled when the gunmen opened fire.
The attack, which began at about 7.30pm on Friday, was the first of its kind in Burkina Faso, a largely Muslim country that had managed to avoid the kinds of jihadist attacks that have destabilised Mali since 2012.
In a separate incident, two Australian humanitarian workers were kidnapped by extremists in northern Burkina Faso.