The U.S. Ambassador to the United Nations, Samantha Power, is traveling to Guinea today and will also visit Liberia and Sierra Leone, making the trip despite calls by some U.S. lawmakers for a travel ban on the three West African countries worst-affected by Ebola.

Power, a member of President Barack Obama’s cabinet, left Washington on Saturday. Obama has resisted Republican calls for a travel ban on advice from health officials who say such a measure would be counter-productive, in part because it would impede people going to help fight the epidemic.

Samantha and Ambassador Toure of Guinea

“For me the benefits of having first hand knowledge of what is happening in these countries gravely outweighs the almost nonexistent risk of actually traveling to these countries provided I take the proper precautions,” Power told reporters before setting off.

Nearly 5,000 people have died in the worst recorded outbreak of Ebola, the World Health Organization said on Saturday, out of more than 10,000 known cases. The epidemic is centered on Liberia, Sierra Leone and Guinea, but there have been a scattering of cases in some other countries, including the United States. The virus is spread through direct contact with bodily fluids from an infected person, and is not transmitted by people who are not showing symptoms.

Power said her role put her in a good position to press for more international action to combat the virus.

“In visiting the three affected countries and getting a detailed grasp of the gaps I hope to use my knowledge of those gaps to shake the trees and really push other countries to do more,” she said.

Power will also visit the headquarters of the United Nations Ebola response mission (UNMEER) in Ghana, which is coordinating global efforts to stop Ebola.

In the United States, concern about the spread of the disease flared anew after the fourth case of the virus was diagnosed: a doctor who was infected after working with Ebola patients in Guinea and who is being treated in New York.

Reported by Reuters