MONROVIA, Liberia (AP) — Poor infrastructure, difficulties with equipment and torrential rains have slowed work for the U.S. military's initial response to the deadly Ebola outbreak in West Africa, but it is now ready to start erecting the main tent for a field hospital in Liberia.

Lt. Col. Jason Brown, who was at the site near the airport in the capital Monrovia, said work is supposed to begin Monday afternoon on the main structure of the 25-bed clinic that will treat health care workers infected with Ebola. It should be ready to accept patients at the end of the month, according to spokesman Chuck Prichard at the U.S. military's Africa Command.

"Every time it rains it slows things down," said Brown, noting that construction for the field hospital was supposed to begin Monday morning and has been pushed to the afternoon. Military teams have also been slowed by equipment that's broken down — including the steering on a road grader — or mix-ups in the delivery of supplies.

On any construction job, there are delays, Brown said, but Liberia presents added challenges.

"Imagine those same frustrations multiplied by a country that has challenges with their infrastructure and challenges with the schedule," he said. But, he said, engineers from the Army, Navy and Marines "have workarounds and solutions for everything."

The Ebola outbreak is believed to have killed more than 3,400 people in West Africa and has taken the biggest toll in Liberia. There aren't enough beds in isolation units to keep up with the hundreds who get sick each week.

The U.S. has also promised to build 17 other Ebola treatment centers, which would have space for 100 patients each. Work on at least two of the clinics has begun, Prichard said.

While the space is sorely needed, some experts are worried about who will staff them. The three hardest-hit countries of Liberia, Guinea and Sierra Leone had too few doctors and nurses to begin with, and a tremendous number of infections in health care workers during the outbreak has only further reduced their numbers. With more than 370 health care workers sickened by the disease so far, many other clinicians are afraid to care for Ebola patients.

The White House said President Obama plans to meet with his national security advisers on Monday to discuss the Ebola outbreak and the administration's response. The Pentagon's spokesman said Friday that up to 4,000 U.S. troops could be deployed to West Africa.

Navy Rear Adm. John Kirby said the military has begun medical testing for Ebola at two new labs in Liberia. Kirby said that the service members are not going to treat patients and are not expected to come in contact with anyone who is infected.

There are about 230 U.S. troops deployed for the Ebola mission now. About two dozen are in Senegal setting up a transportation center and the rest are in Liberia.

___

DiLorenzo reported from Dakar, Senegal.