WHO spokesman Tarik Jasarevic said on Friday that Congo's Ministry of Health had provided updated figures: 45 cases overall since April 4, including 14 confirmed, 10 suspected and 21 probable.
The European Commission has announced a package of urgent humanitarian aid to help contain an outbreak of Ebola in the Democratic Republic of Congo.
It said the new death has epidemiologic ties to another case.
Reports also indicate that 32 people are suspected to have been infected with Ebola viral disease, including three health care workers.
It also followed the announcement by Congo's health ministry of 11 newly confirmed cases in the smaller town of Bikoro, near the northwest village where the virus was first detected.
"One new case of Ebola virus disease has been confirmed in Wangata, one of the three health zones of Mbandaka, a city of almost 1.2 million people in Equateur Province in northwestern Democratic Republic of the Congo", the UN's health agency said in a statement.
The Ebola outbreak in the DRC has entered a "new phase" after it spread to a large city, Health Minister Oly Ilunga said on Wednesday.
DRC now faces a "very high" risk, the World Health Organization said, after the disease was confirmed in one patient in a major city - raising the assessment from "high" previously.
The East African Community (EAC) regional bloc said in a statement Friday it was on "high alert" following an Ebola outbreak in the Democratic Republic of Congo (DRC).
Mbandaka had three suspected cases in addition to the confirmed case. Moreover, WHO said that no restrictions have issued on global travel.
The EU funding announced today will ensure deployment of relevant surge capacity to the affected areas, surveillance and contact tracing of Ebola victims as well as active case finding for early detection of those infected.
The current outbreak involves the same strain of the virus that hit three West African countries in 2013-15 and sparked an worldwide panic.
The Ebola virus is transmitted to humans from animals and has an estimated 50-percent fatality rate, according to the WHO.
Many of these people were in remote areas, Mr Salama said.
Moreover, WHO has deployed 4,000 experimental Ebola vaccines in DRC and more of the vaccines should reach DRC in the coming days. The virus can be fatal in up to 90 percent of cases, depending on the strain. Symptoms include fever, vomiting, diarrhea, muscle pain and at times internal and external bleeding.