WASHINGTON — The Obama administration is ramping up its response to West Africa’s Ebola crisis, preparing to assign 3,000 U.S. military personnel to the afflicted region to supply medical and logistical support to overwhelmed local health care systems and to boost the number of beds needed to isolate and treat victims of the epidemic.

President Barack Obama planned to announce the stepped-up effort today during a visit to the federal Centers for Disease Control and Prevention in Atlanta amid alarm that the outbreak could spread and that the deadly virus could mutate into a more easily transmitted disease.

The new U.S. muscle comes after appeals from the region and from aid organizations for a heightened U.S. role in combatting the outbreak blamed for more than 2,200 deaths.

Administration officials said Monday that the new initiatives aim to train as many as 500 health care workers a week.