"An enhanced UN-wide response is required. . . . We have no time to lose," says David Gressly.
The 19 new infections raise the outbreak total to 1,866 cases amid continued threats.
In another development, arson threats at Masereka health facilities impeded infection prevention steps.
"One of the world's most dangerous viruses in one of the world's most dangerous areas," WHO director-general says.
The Democratic Republic of the Congo's (DRC's) ministry of health confirmed 17 new cases of Ebola today and 16 more deaths in the ongoing outbreak in North Kivu and Ituri provinces.
So far 68% of deaths have occurred outside of Ebola treatment centers, a worrisome statistic.
The new cases raise the outbreak total to 1,739, including 1,147 deaths.
A previously unaffected health zone reports its first case, Korea adds a cash donation, and a group warns of a security clash-related rise in displaced people.
Fifty-six new cases bring the outbreak total to 1,705, including more than 100 infected health workers.
Officials warned of yet another surge in cases and report 23 new infections and 22 probable ones.
