THURSDAY, Oct. 9, 2014 (HealthDay News) -- The heads of West African nations battered by the Ebola outbreak pleaded Thursday with world leaders for massive increases in financial and medical aid.

"Our people are dying," Sierra Leone President Ernest Bai Koroma said by videoconference at a World Bank meeting in Washington, D.C. He called the epidemic "a tragedy unforeseen in modern times," NBC News reported, adding that the world isn't responding fast enough as children are being orphaned and doctors and nurses continue to die.

The calls for help came the same day that the director of the U.S. Centers for Disease Control and Prevention likened the Ebola crisis to the early days of the AIDS epidemic, which also started in Africa.

"In my 30 years in public health, the only thing that has been like this is AIDS," Dr. Tom Frieden said at the World Bank conference. "We have to work now so that this is not the world's next AIDS."

United Nations Secretary-General Ban Ki-moon called for a 20-fold increase in international aid to the beleaguered nations of Guinea, Liberia and Sierra Leone. Representatives gathered for the World Bank meeting pledged medical evacuations for health care responders who catch the virus, the Associated Press reported.

"For those who have yet to pledge, I say please do so soon," he said. "This is an unforgiving disease."

The U.S. military is preparing to build medical centers in Liberia -- the hardest hit country -- and may send up to 4,000 soldiers to help with the Ebola crisis. Other nations, including Germany and Great Britain, have also pledged support, the AP reported.

In the United States, stepped-up screening measures for Ebola will begin Saturday at JFK International Airport in New York City, the first of five major U.S. airports that will start screening travelers entering the country from West Africa.

The five airports receive 94 percent of the roughly 150 travelers who arrive daily in the United States from the West African nations hit hardest by the Ebola outbreak -- Guinea, Liberia and Sierra Leone, Dr. Tom Frieden, director of the U.S. Centers for Disease Control and Prevention, said during a Wednesday news briefing.