WASHINGTON — In an effort to stem the tide of veterans suicides, President Donald Trump on Tuesday will sign an executive order mandating new mental health options for recently separated service members.

Federal officials estimate about 20 veterans a day nationwide take their own lives, but outside advocates say they believe that number could be even higher. The departments of Veterans Affairs and Defense have launched numerous initiatives in recent years to increase outreach to at-risk veterans, with mixed results.

The new executive order will require those two bureaucracies and the Department of Homeland Security within 60 days to establish new plans for “seamless mental health care” for troops leaving the military services.

Once written, the agencies will have another six months to put the new reforms into place.

The plans could include expanded VA health services, extended access to Defense Department resources, more availability for care in the private sector, or some combination of all of those options.

White House officials familiar with the new order said the plans are also expected to include changes to the military’s post-service transition programs, to put a bigger emphasis on mental health care importance and availability.

On the campaign trail and in his first year in office, Trump has made helping veterans a frequent talking point. But most of that focus has been on reforms to the VA system, issues of accountability with department employees and expanding private-sector care options for veterans.

Officials said the new order is not mean to condemn work done on the issue by military and VA officials so far, but to give an extra public boost to the issue, and to set clearer, quicker timelines for results.

VA Secretary David Shulkin has called the issue of veterans suicide his top clinical priority, and last year updated department rules to allow veterans with other-than-honorable discharges to receive emergency mental health services at VA hospitals.

The new executive order will also include more outreach to those veterans, seen as a particularly at-risk population because of their limited access to military health care and benefits.

The focus on recently-separated veterans is also because of that group’s risk of suicide. Research by the Naval Postgraduate School has found that veterans in their first year out of the military are almost three times more likely to take their own lives than individuals still serving.

Including the Department of Homeland Security in the executive order is meant to ensure that members of the Coast Guard are also included in all prevention initiatives.

The moves are not expected to require additional funding, though White House officials have told the departments they are open to supplemental funding if a need is found.