The US Centers for Disease Control and Prevention said more staff had been sent to a border city in the Democratic Republic of Congo to manage Ebola cases there.
The outbreak, which began a year ago has now killed more than 1,800 people.
The agency indicated it would send more staffers if armed conflict in the north eastern region subsided to safer levels.
Twelve CDC employees will go to Goma, a major transit city near the Congolese border with Rwanda. On Thursday, the city confirmed its third case of Ebola.
CDC Director, Dr. Robert R. Redfield said on Twitter that armed conflict was hampering health officials’ attempts to manage the outbreak, “increasing the risk of disease spread.”
Henry Walke, CDC director of preparedness and emerging infections, said the agency could add more staff if safety improves enough.
The CDC said it is working with the U.S. State Department to determine if it is safe to send more U.S. health workers to areas outside Goma.
The announcement came hours after Rwanda briefly closed the border it shares with the Congo over fears the disease would spread.
Witnesses said authorities prevented most people from crossing between the Rwandan city of Gisenyi and Goma for several hours, after the Ebola virus was detected in Goma. The only people allowed to cross were Congolese nationals in Rwanda returning home.
Rwanda’s ministry of health denied the border was ever closed, and by Thursday afternoon people were crossing between the cities again.
Congolese health officials said the 1-year-old daughter of a man who died of the virus earlier this week is showing symptoms of the disease, in the city’s third confirmed Ebola case.
The man was diagnosed a few days after arriving in Goma from a northeastern rural community in Congo’s Ituri province.
Earlier this month, a pastor tested positive and later died after arriving in Goma by bus, prompting the World Health Organization (WHO) to declare the Ebola outbreak in Ituri and the conflict-ridden North Kivu province a global health emergency.
The brief shutdown ran counter to a plea made by the international health officials for countries not to close their borders or impose restrictions on travel to the DRC.
WHO spokeswoman Dr. Margaret Harris said it is vital that more people who are at risk receive the vaccine used to combat the spread of the virus.
She said the vast majority of such people accept the vaccine, but to be effective, “we really need 100 percent acceptance.”
Harris said health officials also struggle to identify those who “hide” and “flee” to avoid “being identified as a high risk contact.”
She said many of them “think that being taken to the Ebola treatment center is like being taken to the death house” when the centers actually provide “an incredibly high standard of care.”
Harris said if people experiencing early symptoms such as fevers and headaches report to a center in a timely fashion, there is a “90 percent chance of survival.”
2,600 cases of Ebola
More than than 2,600 cases of Ebola have been reported in Congo since the current outbreak began a year ago, with a death rate of nearly 70 percent.
This is the 10th outbreak of the virus over the last four decades in the DRC.
It is the second largest outbreak after the historically deadly 2014 epidemic in West Africa that killed more than 11,300 people.