WASHINGTON (AP) — 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 Tuesday 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 officials, speaking on the condition of anonymity to discuss the plans ahead of Obama's announcement, said the cost of the effort would come from $500 million in overseas contingency operations, such as the war in Afghanistan, that the Pentagon already has asked Congress to redirect to carry out humanitarian efforts in Iraq and in West Africa. Ebola is spread through direct contact with the bodily fluids of sick patients, making doctors and nurses especially vulnerable to contracting the virus, which has no vaccine or approved treatment. White House press secretary Josh Earnest, responding to criticism that the U.S.