In this Jan. 25, 2018 file photo, Sen. Jon Tester (D-Mont.) arrives for voting at the Capitol in Washington. (J. Scott Applewhite/AP)

President Trump called for Sen. Jon Tester (D-Mont.) to resign Saturday over the release of allegations that led White House physician Ronny L. Jackson to end his bid to lead the Department of Veterans Affairs.

Trump tweeted that the Secret Service told him that allegations against Jackson were “not true,” and he suggested that voters should punish Tester, who is defending his seat in a state that strongly supported the president in 2016, at the polls this year.

The president said on Twitter that the Secret Service has found the allegations released Wednesday by Tester’s staff to be untrue. However, in a public pronouncement Friday, the agency only said that a review of records offered no evidence of an allegation reported by CNN that agents had to intervene on an overseas trip in 2015 to prevent Jackson, who was found banging on the door of a hotel room, from disturbing then-President Barack Obama.

“Secret Service has just informed me that Senator Jon Tester’s statements on Admiral Jackson are not true,” Trump tweeted as he left the Trump National Golf Club in Sterling, Va., for a rally in Michigan. “There were no such findings.”

Officials at the Secret Service and the White House did not immediately respond to questions about Trump’s tweets.

Later Saturday, at the campaign-style rally in Michigan, Trump accused Tester of a smear campaign and again called for him to resign.

“I know things about Tester that I can say, too,” Trump said at the rally. “And if I said them, he’d never be elected again.”

Jackson, a Navy rear admiral and former combat physician who served in Iraq, remains under heightened scrutiny as the president’s doctor after the release of the allegations last Tuesday, including accusations that he drank on the job, improperly prescribed and dispensed medications and contributed to a toxic work environment.

While Trump, Jackson and other White House officials have vehemently denied the allegations, they have been difficult to prove or disprove. Tester’s staff has released no documentation for the accusations, offering only that each charge is supported by the accounts of at least two individuals.

Even in the case of the CNN report, the Secret Service’s statement does not prove that the incident did not happen. According to one former employee of the White House Medical Unit, as well as a Democratic aide with knowledge of the allegations that Tester released, the CNN report, which claimed that the incident occurred in 2015, was incorrect; it occurred in 2014, they said. The Secret Service pronouncement specified only that records from 2015 showed no evidence of such an incident.

More allegations have trickled in since Thursday, when Jackson ended his bid to lead VA, and they are being referred to the inspector general’s office within the Defense Department, according to a Democratic aide.

The Senate Veterans’ Affairs Committee, where Tester serves as ranking Democrat, no longer has jurisdiction over Jackson’s performance now that his bid to run VA has ended.

The tweets by Trump appeared poised to intensify the conflict between the White House and Tester over Jackson’s failed nomination — and to spill into election-year politics.

“Tester should lose race in Montana,” the president tweeted. “Very dishonest and sick!”

The Democratic aide said aides to the panel’s chairman, Johnny Isakson (R-Ga.), sat in on some interviews with Jackson’s current and past colleagues, and that what those aides heard helped spur Isakson to call for the postponement of Jackson’s confirmation hearing, which was supposed to take place last Wednesday. Isakson did not object to the release of the allegations.

While The Washington Post has interviewed numerous current and former employees of the White House Medical Unit who claimed to have observed Jackson drinking and improperly prescribing and dispensing medications, no evidence has emerged to support one of the more damaging allegations — that he had crashed a government vehicle after drinking at a Secret Service going-away party.

On Friday, White House officials said they had thoroughly reviewed Jackson’s vehicle records and found three minor incidents but no evidence of the crash as described in the allegations last week.

Tester declined to directly address Trump’s attacks or a White House claim that there was no crash. Instead, his office issued a statement saying that it is his “duty to make sure Montana veterans get what they need and have earned.”

“I’ll never stop fighting for them as their senator,” he stated.

Other senators involved in confirming a VA nominee to lead VA were mostly silent Saturday about the developments. Aides to Isakson declined to provide another statement Saturday. Requests for comment from other committee members, including Sens. Jerry Moran (R-Kan.), Thom Tillis (R-N.C.) and Dan Sullivan ­(R-Alaska), were not returned.

Seung Min Kim and David J. Lynch contributed to this report.