The Justice Department is launching a federal civil rights investigation into the death of Eric Garner, who was killed by an NYPD officer during a chokehold arrest last July, US Attorney General Eric Holder announced Wednesday evening.

“Our prosecutors will conduct an independent, thorough, fair and expeditious investigation,” he said, adding that the probe will look into potential civil rights violations.

The announcement came just after a grand jury cleared cop Daniel Pantaleo of all charges in the chokehold death case.

“His death, of course, was a tragedy,” Holder said. “All lives must be valued.”

The investigation will include a “complete review” of what was presented to the Staten Island grand jury.

President Obama made a statement at the White House Tribal Nations Conference on Wednesday evening, saying he had spoken with Holder.

“We are not going to let up until we see a strengthening of the trust and a strengthening of the accountability that exists between our communities and our law enforcement,” he said.

“I’m not interested in talk, I’m interested in action,” Obama added.

Pantaleo — who was placed on modified duty after Garner’s death July 17 — is also being investigated by the NYPD’s Internal Affairs Bureau, which could charge him departmentally.

After a trial, the Department Advocate’s Office will make recommendations to Police Commissioner Bill Bratton as to whether Pantaleo should be fired, disciplined or go unpunished.

Ultimately, Bratton has the final say in his future on the force.

A police source said it’s likely the Department Advocate will recommend that Pantaleo be disciplined.

“The chokehold, however not criminal, does violate the patrol guide procedure in section 203 ‘use of force,’” the law enforcement source said.

The Civilian Complaint Review Board has also received complaints regarding the chokehold case — and will likely reactivate its investigation now that the grand jury probe is over.