The Pentagon official who oversaw the successful effort to remove chemical weapons from Syria and Libya is leaving his post to help coordinate America’s and international efforts to contain the deadly Ebola outbreak in West Africa and prevent its spread within the U.S.

Andrew C. Weber, the assistant secretary of defense for nuclear, chemical and biological defense programs for the past six years, is resigning to assist former ambassador Nancy Powell, whom President Barack Obama named earlier this month as the State Department’s coordinator for the anti-Ebola campaign. Weber declined requests for comment. But Administration officials who spoke on background said that Weber, who has served as Obama’s adviser at the Defense Department on non-proliferation issues, will serve as deputy to Powell.

Administration officials hope that the addition of a skilled Defense Department veteran of politically sensitive and logistically complex chemical weapons removal projects will strengthen the Obama administration’s response to the epidemic which has swept through West Africa, infecting and killing thousands and devastating their national economies. Many public health experts say that efforts so far to contain the virus have been hampered by poor outreach to and coordination among governments and international relief groups.

Weber’s appointment is one of several steps that Obama and his team have quietly authorized to boost the effectiveness of America’s response to the epidemic. The World Health Organization estimates that Ebola, which normally kills about over 50 percent of infected humans, has already infected some 7,400 people and killed about 3,400, mainly in West Africa.

On Friday, senior public health and emergency preparedness officials outlined some of the steps being taken to stop the spread of the epidemic, the deadliest in recent history. But in addition, the White House has quietly approved and taken other steps – such as Weber’s job shift -- to improve Washington’s response to the outbreak, limit its devastating effects, and prevent its spread to and within the U.S..

For one, officials said, the administration has involved the U.S. Army Medical Research Institute of Infectious Diseases, the Pentagon’s top bio-defense lab and a crucial source of expertise on Ebola and other lethal pathogens. The Washington Post reported earlier this month that the RIID, as it is known, has sent several experts to Africa. Officials said that the institute, which has worked in the region on Lassa fever and other dangerous hemorrhagic killers since 2006, has already begun operating a small research lab in Liberia. The administration has also authorized the Navy to open two labs in West Africa, one of which began operating last week in Liberia.

In his Pentagon job, Weber oversaw the Defense Threat Reduction Agency, which has also been monitoring Ebola. DTRA helped develop ZMapp, the experimental Ebola treatment which was given to two American public health workers who contracted the virus while working in Africa and survived. Two other vaccines are also in early stages of testing.

Critics have charged that American and international public health authorities were too slow in responding to the epidemic, which is believed to have begun in Guinea late last year.

In mid-September, Obama declared the Ebola outbreak a “national security priority,” saying the world has a “responsibility to act" to contain the deadliest Ebola outbreak in history. He said that the U.S. would devote substantial resources -- precisely how much the White House has not said -- to stopping the spread of the disease. Obama noted that the epidemic would “get worse before it gets better.” He also announced that the U.S. military would lead the effort -- called Operation United Assistance -- and ordered the deployment of over 3,000 U.S. soldiers to build high-containment labs and treatment centers for those infected. An army spokesman said Friday that the total might rise to 4,000, depending on conditions on the ground. Ambassador Powell left her ambassadorial post in India in March following a dispute between Washington and New Delhi over the arrest of a junior Indian diplomat in New York. Powell, who has held several key posts in Asia, too, has experience in combating disease outbreaks. She previously served as the State Department’s avian flu coordinator.

The World Health Organization has been widely criticized for its slow response to the epidemic. Although the first Ebola cases emerged in late 2013 in Guinea, the agency, beset by budget cuts and a loss of veteran experts, did not declare an outbreak until March, when it warned that 49 cases had been confirmed, along with 29 deaths. It did not declare an international public health emergency until August.

Concerned about the possible spread of the deadly virus to the U.S., Obama became personally involved this summer, officials said. On Friday, the White House announced that he had gotten an update on the epidemic from Gen. David Rodriguez, the commander of U.S. Africa Command (AFRICOM), with whom he spoke by phone. The military’s Joint Force Command began deploying the first of some 3,200 soldiers to West Africa in mid-September to build the field hospitals and mobile treatment centers, but that effort, too, has gone slowly.