US military service chiefs condemn racism, stand up for military values after Charlottesville It's rare for the nation's top military leaders to weigh in on political events.

 -- The heads of the U.S. Army, Navy, Air Force and Marine Corps have weighed in on Twitter in the wake of last weekend's violent clashes in Charlottesville, Virginia, condemning racism and standing up for military values.

It is rare for the nation's top military leaders to weigh in on political events because of the Department of Defense's tradition of remaining apolitical.

Adm. John Richardson, chief of naval operations, first posted on Saturday night, calling the events in Charlottesville "unacceptable" and saying the U.S. Navy "stands against intolerance and hatred."

Earlier that day, a woman was killed and several others were injured after a car rammed into demonstrators protesting against white nationalists. James Alex Fields Jr., 20, is charged with second-degree murder, three counts of malicious wounding, and one count related to leaving the scene in the incident.

The Army confirmed Sunday evening that Fields had briefly attended Army basic training in 2015, but was released due to a failure to meet training standards.

Gen. Mark Milley, the Army's chief of staff, tweeted Wednesday morning, "The Army doesn't tolerate racism, extremism, or hatred in our ranks. It's against our Values and everything we've stood for since 1775."

Also weighing in was Gen. Robert Neller, commandant of the Marine Corps, who posted on social media Tuesday, shortly after it was reported that a leader of a white supremacist group -- whose members marched in Charlottesville over the weekend -- was a former Marine recruiter.

Neller tweeted that there is "no place for racial hatred or extremism" in the Marines.

Former Staff Sgt. Dillon Hopper, the reported leader of the neo-Nazi group "Vanguard America," served in the Marine Corps for 11 years and completed two deployments, later becoming a recruiter.

The Marines issued a statement in response to Hopper's service, condemning hate and extremist groups.

"We are proud of the fact that Marines come from every race, creed, cultural background and walk of life," the statement said, adding, "The guidance to Marines is clear: participation in supremacist or extremist organizations or activities is a violation of Department of Defense/Marine Corps orders and will lead to mandatory processing for separation."

This morning, Gen. Dave Goldfein, chief of staff for the Air Force, joined his fellow service chiefs, saying "we're always stronger together" and espousing Air Force values of "integrity, service and excellence."

On Monday, Secretary of Defense James Mattis told reporters he was "very saddened" by the violence he saw in Charlottesville, but wouldn't comment further about the events of that weekend or Fields' military service.

“I don't know the circumstances around this young man's four months,” he said in reference to Fields' short stint in Army basic training.

“I don't want to comment on it, but generally speaking we don't sign people up for four-month tours of duty. So, once the full reality is out, I'm sure you'll have an explanation how he came in and out, but I can't comment on it. Right now, I just haven't seen it," Mattis said.