It is possible to contain the latest Ebola outbreak in Congo, but it will be difficult unless the right steps are taken within the next two weeks, a World Health Organisation official said on Friday.

Democratic Republic of Congo's health ministry last week declared the country's first Ebola outbreak in three years. It is the country's 16th outbreak overall and the first in Kasai province since 2008.

The latest data from the health ministry in Kinshasa said there were 32 suspected cases, 20 confirmed cases and 16 deaths.

Containing the outbreak is "possible, but it will be challenging if we miss the window of opportunity," WHO Programme Area Manager Patrick Otim told a Geneva briefing, calling for more support for the government and other partners.

"We have the expertise, DRC has the expertise, but we need to be able to get the people and supplies into place and we need to be able to pay for the operations."

The WHO said last week that Congo had a stockpile of treatments as well as 2,000 doses of the Ervebo vaccine, which would be transported to Kasai to vaccinate frontline health workers and people who came into contact with patients.

Otim said on Friday that 400 doses had arrived at the outbreak's epicentre in the city of Bulape, and that the campaign could begin on Saturday.

He said the WHO plans to request an additional 40,000-50,000 Ebola vaccine doses for Congo.

Several aid workers have told Reuters that Congo could struggle to mount an effective response given recent cuts to foreign assistance and the dismantling of the U.S. Agency for International Development under President Donald Trump.

There is limited capacity to respond to the outbreak in Kasai and new treatment facilities need to be set up there "as the outbreak may expand," Otim said, noting that one new case was confirmed 70 kilometres from the current epicentre.

There is moderate risk of the outbreak spreading to other countries "with the most prioritised country being Angola," Otim said.