"Secret Service has just informed me that Senator Jon Tester's statements on Admiral Jackson are not true," Trump tweeted. "There were no such findings. A horrible thing that we in D.C. must live with, just like phony Russian Collusion. Tester should lose race in Montana. Very dishonest and sick!"
"Allegations made by Senator Jon Tester against Admiral/Doctor Ron Jackson are proving false... Tester should resign," Trump tweeted on Saturday.
"Admiral Jackson is the kind of man that those in Montana would most respect and admire, and now, for no reason whatsoever, his reputation has been shattered. Not fair, Tester!," Trump added.
Jackson, a U.S. Navy rear admiral who has been physician to three presidents, has categorically denied the accusations as false. Trump doubled down on his criticism of Tester in a tweet later on Saturday.