GENEVA — The World Health Organization said Friday that a six-week-old outbreak of the deadly Ebola virus in Democratic Republic of Congo was worrisome and must be aggressively controlled, but does not warrant its top designation as an international public health emergency.

The organization’s emergency committee, meeting in Geneva, said public health authorities and aid organizations were in a strong position to halt the highly contagious disease even though it has now spread to an urban area.

Dr. Robert Steffen, chairman of the emergency committee, told a telephone news conference after the meeting that the early detection of the outbreak and the preparations to stop its spread provide “a strong reason to believe that this situation can be brought under control.”

The top crisis-level designation of “Public Health Emergency of International Concern” is invoked by the organization’s emergency committee to galvanize international action and provide advice on how to contain a deadly and contagious malady threatening to spread uncontrollably across borders and continents.