It is the first state of emergency announced under Prime Minister Abiy Ahmed, who came to power in 2018 and won last year's Nobel Peace Prize in part for expanding political freedoms in the authoritarian nation.
"Because the coronavirus pandemic is getting worse, the Ethiopian government has decided to declare a state of emergency under Article 93 of the constitution," Abiy said in a statement.
"I call upon everybody to stand in line with government bodies and others that are trying to overcome this problem," he added, warning of "grave legal measures" against anyone who undermines the fight against the pandemic.
It was not immediately clear how the state of emergency would affect day-to-day life in Ethiopia, where the government has so far refrained from imposing a lockdown similar to those in effect elsewhere in the region, including in Rwanda, Uganda and Mauritius.
According to the country's constitution, under a state of emergency the Council of Ministers has "all necessary power to protect the country's peace and sovereignty" and can suspend some "political and democratic rights".
The constitution also says lawmakers need to approve a state of emergency, which can last for six months and be extended every four months after that.
Since reporting its first COVID-19 case on March 13, Ethiopia has closed land borders and schools, freed thousands of prisoners to ease overcrowding, sprayed main streets in the capital with disinfectant, and discouraged large gatherings.
The country's electoral board also announced last week that landmark general elections planned for August would need to be postponed because of the pandemic.
It did not provide a timeline for when the elections would ultimately be held.
Lawmakers' constitutional mandates expire in October, but a state of emergency could enable them to stay in their seats, though it raises the possibility of strong objections from the political opposition. (AFP) CPS