The President made the declaration in a televised statement on Friday evening amid intensified control measures against the deadly virus.
The proclamation orders closure of non-essential commodity shops, bars, cafés, casinos, sporting venues, and all forms of public gatherings in bid to stop the spread of the virus.
The Gambian leader has also ordered all public and private institutions to minimise staff reporting to work with immediate effect.
The Gambia so far recorded three cases involving two Gambians and one Bangladeshi man who succumbed to the virus last week. The Health Ministry said all the three cases were imported and that contact tracing is underway to isolate all those who interacted with them.
The move came days after the suspension of all public gatherings including religious convergence. Muslims in the country have for the first time desist from the weekly Friday prayers in observance of the ban on public gatherings.
Streets in Banjul and Serekunda, Gambia's biggest suburb are gradually getting less busy, with few motorists plying the roads. Beaches and restaurants in the Tourism Department Area are literally empty as most tourists cut their holidays short to returned home prior to the closure of land borders and airspace in wake to the pandemic.
The Health ministry said 47 suspected cases tested at the Medical Research Council are awaiting laboratory results.
"I urged all to take the pandemic seriously," the president said. He cited the need to apply the prescribed preventive measures including public spacing and hand washing using sanitisers in keeping safe from the virus.