A hostile environment in the eastern Democratic Republic of the Congo (DRC) is hampering the response to an Ebola outbreak, UN humanitarians warned on Monday.

The UN and its humanitarian partners said that insecurity, population movements and displacement are significantly complicating surveillance, contact tracing and response efforts against a backdrop of violence, food insecurity and severe humanitarian needs.

The outbreak is centered in the eastern province of Ituri, where more than 482 suspected cases have been reported since April, including eight confirmed cases and around 116 deaths among suspected cases across several health zones, according to the UN Office for the Coordination of Humanitarian Affairs (OCHA).

Nearly 10 million people across Ituri, North Kivu and South Kivu are facing crisis or worse levels of hunger, further straining fragile health systems, said OCHA.

The UN and its partners are supporting the government-led Ebola response, it said.

OCHA said that more than 5 tonnes of medical supplies were airlifted on Sunday to Ituri by the World Food Programme.

The office said that additional resources and sustained humanitarian access will be critical to contain the outbreak and prevent further spread.

"Testing of suspected cases is ongoing. A case was also confirmed yesterday in Goma, in the province of North Kivu, raising concerns about potential spread in a densely populated urban area," OCHA said.

On Sunday, the World Health Organization declared the Ebola outbreak in the DRC and Uganda a public health emergency of international concern, highlighting the high risk of further spread and the likelihood that the outbreak may be larger than currently detected.

According to authorities, the outbreak involves the Bundibugyo strain of the Ebola virus, for which there is no vaccine.

"The UN calls on the international community to urgently scale up support for both the Ebola response and the broader humanitarian response in the DRC," OCHA said. "Without immediate action, life-saving assistance will not reach those most in need and critical humanitarian gains risk being reversed."

The office said the humanitarian response plan for the DRC is just 34% funded.