Liberia is marked as effectively Ebola-free by the World Health Organisation, joining Sierra Leone and Guinea, and ending the world's worst outbreak of the disease.
Wednesday's announcement came 42 days after the last case was confirmed in Liberia, the last of three West African countries with active transmission of the virus.
However, the organisation has warned of risks that the disease, which killed more than 11,300 people out of 28,600 cases during the epidemic, could flare up again.
READ MORE: What is Ebola?
"The risk of re-introduction of infection is diminishing as the virus gradually clears from the survivor population, but we still anticipate more flare-ups and must be prepared for them," Dr Bruce Aylward, WHO's Special Representative for the Ebola Response, said in a statement.
"A massive effort is under way to ensure robust prevention, surveillance and response capacity across all three countries by the end of March," Aylward said.
The country had previously declared itself virus-free in May and September of 2015, but each time a fresh cluster of cases appeared.
READ MORE: Guinea declared free from Ebola after 2,500 deaths
A country is declared Ebola-free 42 days after the recovery or death of the final patient and if there are no new infections.
Russia's 'highly effective' vaccine
Earlier on Wednesday, Vladimir Putin announced that Russian scientists had created a medicine for fighting Ebola that has shown "high efficiency".
"We have registered a medicine for the Ebola fever that, after relevant checks, has shown high efficiency, higher than the remedies used across the world up until now," the Russian president said in a meeting of senior officials, state news agency TASS reported.
Earlier, Anna Popova, Russia's chief state doctor, said that the vaccine would be tested on Russians travelling to parts of the world suffering from the virus, the Interfax news agency reported.
Ebola, which was discovered in 1976 and is transmitted through contact with blood and other bodily fluids, causes massive haemorrhaging and has a death rate of up to 90 percent if left untreated.