The WHO said no new infections have been recorded since May 25.
He said Nigeria must prepare before detecting the first Ebola case rather than responding after infections emerge.
Mr Ghebreyesus said that it was the largest first-month caseload of any Ebola outbreak in Africa.Â
WHO has issued its first comprehensive clinical guidelines for filovirus diseases as DRC battles an Ebola outbreak caused by the Bundibugyo virus.
Oxfam says a lack of access to clean water hampers efforts to contain the spread of the deadly Ebola virus in the Democratic Republic of Congo.
The Coalition for Epidemic Preparedness Innovations awarded $1.9 million to accelerate the development of a vaccine candidate against the Bundibugyo ebolavirus.
The EU Crisis Commissioner, Hadja Lahbi, said the response extended beyond containing the virus.
Authorities have also reported attacks on burial teams and treatment centres involved in the response.
The UN and its partners are sustaining efforts to contain Ebola outbreaks DRC and Uganda, while warning that insecurity and misinformation remain major obstacles to the response.
Mr Dujarric also sent condolences to the people and Government of Nigeria.
