President Obama plans to announce a significant boost in the U.S. response to the worst Ebola outbreak in history in West Africa, including more involvement of the U.S. military, according to an administration official.

Among the likely moves are setting up more field hospitals, sending more health-care personnel and training health workers in the hardest-hit countries of Liberia, Sierra Leone and Guinea. The Pentagon announced last week that it would send a 25-bed hospital to Liberia. The hospital is intended to treat health-care workers, including Liberians, and eventually will be turned over to the Liberian government. But it will be at least a month before the hospital is delivered. “There will be some additional facilities in the works,” the official said.

Obama is expected to lay out details during his visit to the Centers for Disease Control and Prevention in Atlanta on Tuesday, the official said.

“The president considers this a top national security issue, and on Tuesday, you’ll hear him give a detailed response commensurate to that. It’s going to be a whole government-wide response and he will call upon some additional assets to help him effect this mission,” said the official, who spoke on the condition of anonymity because planning is still underway. He declined to provide specifics, saying only, “He will speak to an amped-up response.”

He said high-level planning by top officials from the CDC, the Pentagon, the State Department, the U.S. Agency for International Development and the National Institutes of Health has been taking place for some time about options for a U.S. response. The most recent high-level meeting was convened by Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, at the Pentagon last Wednesday.

President Obama announced Tuesday that the U.S. will lead efforts to combat the Ebola outbreak in West Africa, pledging to dispatch 3,000 military personnel to the region. (WhiteHouse.gov)

As the situation on the ground has worsened, health advocates and aid groups have criticized the adequacy of the U.S. response in the wake of Obama’s remarks a week ago. The administration’s decision to involve the military in providing equipment and other assistance for international health workers in Africa comes after mounting calls from some unlikely groups — most prominently the international medical organization Doctors Without Borders — pressed the urgency of the issue.

The epidemic, which has killed at least 2,400 people in five African countries, is unlikely to spread to the United States in the short term, Obama said Sept. 7 on NBC’s “Meet the Press.” But if the United States and other countries do not send equipment, health workers and other supplies to the region, the virus could mutate to become more transmissible, he said.

“And then it could be a serious danger to the United States,” Obama said on the show.

“We’re going to have to get U.S. military assets just to set up, for example, isolation units and equipment there,” he said, “to provide security for public health workers surging from around the world.”

The United States has spent $100 million in the region, and if Congress approves additional aid requests, the total U.S. commitment would exceed $250 million. At the same time, infectious-disease experts and global health advocates are warning that the infection rate is soaring exponentially, particularly in Monrovia, the capital of Liberia, where patients are dying on the street because there aren’t enough beds in treatment centers.

Depending on the situation, the United States may seek to bolster the funding request. “I don’t want to close the door to potential additional funding,” the official said.

The Defense Department has asked Congress for permission to reprogram about $500 million in the current budget for humanitarian aid for Ebola and Iraq, but without a specific breakdown. That is to allow for flexibility, the official said. “My understanding is that if the Ebola response requires 90 percent of the funds, those funds will go to Ebola.”