The U.S. and other countries have pledged to help in the Ebola crisis. But, with infection rates doubling every three weeks, can international aid come soon enough?

"Right now there's a huge momentum in terms of nations doing pledges for Ebola. We've seen in many other crises that people pledge, but don't deliver," says Dr. Joanne Liu is the International President of Doctors without Borders and she addressed this meeting at the UN yesterday.

"My key message is thank you very much for the pledges; thank you very much for the UN Security Council resolution, but now this needs to translate into real action on the field if we want to make a difference," says Dr. Liu, adding that a blank check is not enough. 

There's not enough people on the ground to respond to epidemic that has left thousands of people dead, she said.