for Supreme Court fight Hillicon Valley: Murky TikTok deal raises questions about China's role | Twitter investigating automated image previews over apparent algorithmic bias | House approves bill making hacking federal voting systems a crime MORE (R.I.) raise concerns about the potential overlap between Trump's role as president and his private business interests.

"Previous Presidents have provided friends and even campaign donors tours of Air Force One, but the reports that members of the President's private club may have received such tours are particularly troubling because their relationship to the President arises out of an ongoing business relationship with the President," the senators wrote.

The letter asks the inspectors general for a "review of all individuals who have had access to Air Force One for tours or other nonofficial travel"since Trump took office last year.

It also asks the internal watchdogs to make a determination as to whether any of the individuals who received tours of the aircraft had business relationships with Trump or his family and whether such relationships played a role in the decision to invite them aboard the plane.

Trump has faced scrutiny since taking office for his far-reaching business dealings, with critics and ethics watchdogs raising concerns that his business interests could conflict with his responsibilities as president.

As he prepared to take office last year, Trump passed off day-to-day control of his business empire to his two adult sons. But he also declined to put his assets in a blind trust and fully divest from his business.

BuzzFeed News obtained an invitation for the Air Force