The head of the World Health Organization said Monday that the fast-moving Ebola outbreak in the Democratic Republic of Congo and Uganda is outpacing response efforts, with suspected deaths now at 220.

Addressing an online meeting of the African Union, WHO Director-General Tedros Adhanom Ghebreyesus said a delay in detecting cases means responders are "playing catch-up." He warned the epidemic is likely to get worse before it gets better.

Tedros said he will travel to Congo, the epicenter, on Tuesday with Dr. Chikwe Ihekweazu, the WHO's head of health emergencies.

Earlier Monday, neighboring Uganda reported two new Ebola cases, bringing its total to seven. Tedros said other countries bordering Congo are at high risk and should take immediate action.

The WHO has declared the outbreak of the rare Bundibugyo strain a public health emergency of international concern. Containment is complicated by high insecurity in Congo’s Ituri and North Kivu provinces and the lack of approved vaccines for this strain.