The three countries hit hardest by the Ebola epidemic have recorded the fewest weekly new infections in months, according to the World Health Organization (WHO).
As the global death toll reached 8,429 out of 21,296 cases reported so far, Sierra Leone and Guinea both saw the fewest weekly confirmed Ebola cases since August 2014.
Liberia, which reported two days with no new cases last week, had its lowest weekly total since June, the WHO said on Wednesday.
Ban Ki-moon, the U.N. secretary-general, previously said the epidemic could be over by mid-2015, but the WHO is now declining to set a specific timeline, after having to backtrack on previous predictions.
"WHO hopes Ebola ends as soon as possible in all three affected countries of Sierra Leone, Liberia and Guinea," said Winnie Romeril, the organization’s spokeswoman. But she added that getting to zero cases would take time and effort.
Ernest Bai Koroma, Sierra Leone's president, predicted this week that his country would be Ebola-free by WHO standards by May.
Under the U.N.’s health agency, a country cannot be declared Ebola-free until it has registered no cases for 42 consecutive days.
Al Jazeera and wire services