White House chief of staff John Kelly — who is expected to call it quits in the days ahead — was interviewed by special counsel Robert Mueller’s team, CNN reported Friday, citing a trio of sources.

Kelly answered a narrow set of questions from investigators in recent months after White House lawyers objected to Mueller’s initial request to do the interview earlier this summer, the sources said.

Kelly is the latest high-ranking White House official known to have given information for Mueller’s probe.

Most of the other witnesses interviewed were connected to Trump’s campaign, but Kelly didn’t join the administration until after the president was sworn in in January 2017.

Mueller’s team asked Kelly — who the network earlier reported was no longer on speaking terms with Trump — about what he remembered about Trump’s attempt to fire Mueller and whether the president had tried to obstruct justice.

The White House counsel’s office at first fought the Mueller request to talk to Kelly, a retired Marine general.

One source told the network that Emmett Flood wanted to make sure “ground rules” were negotiated.

“In order to question a government official about things that happened during the course of government business, you’ve got to show that it’s highly important and you can’t get it anywhere else,” the source said.