WASHINGTON — The American strategy on Ebola is two-pronged: Step up desperately needed aid to West Africa and, in an unusual step, train U.S. doctors and nurses for volunteer duty in the outbreak zone. At home, the goal is to speed up medical research and put hospitals on alert should an infected traveler arrive.

With growing criticism that the world still is not acting fast enough against the surging Ebola epidemic, President Barack Obama has called the outbreak a national security priority.

Obama is to travel to Atlanta on Tuesday to address the Ebola crisis during a visit to the Centers for Disease Control and Prevention, the White House said. During his visit, Obama is to be briefed about the outbreak and discuss the U.S. response with officials.

The administration hasn’t said how big a role the military ultimately will play — and it’s not clear how quickly additional promised help will arrive in West Africa.

“This is also not everything we can and should be doing,” Sen. Chris Coons, D-Del., who chairs a Foreign Relations subcommittee that oversees African issues, told the Senate last week.