Presumptive Republican Presidential nominee Donald Trump is considering retired Lieutenant General Michael Flynn as a potential vice-presidential running mate, according to multiple reports.

Trump’s potential vice president list includes Indiana Governor Mike Pence, former House speaker Newt Gingrich and New Jersey Governor Chris Christie. Many of Trump’s associates have reportedly urged the real estate mogul to pick a seasoned governor or senator who could help unite the Republican party, currently divided over Trump.

The Trump campaign was not available for comment, reports said. A source told the Washington Post, “Trump-Flynn. I’ve heard him say that, kind of test out the sound of it. I think it’s a brand he finds appealing.”

News of the Trump campaign formally vetting Flynn as the 70-year-old’s running mate was first reported by the New York Post. In an interview with the American daily, Flynn said, “All I would say is that I have been honored to serve my country for the past three decades and look forward to serving in other ways now that I am retired from the U.S. Army. I’ve been a soldier too long to refuse to entertain any request from a potential commander in chief.”

Flynn, ex-chief of the Defense Intelligence Agency under President Barack Obama from 2012 to 2014, had been acting as Trump’s foreign policy adviser since at least February, reports said. A registered Democrat, Flynn is a harsh critic of President Obama and the American political establishment. His 2014 retirement reportedly came after numerous reports of him locking horns with several colleagues like then Undersecretary of Defense for Intelligence Michael Vickers.