Bill Barr, top henchman, in this up to his neck

President Trump pushed the Australian prime minister during a recent telephone call to help Attorney General William P. Barr gather information for a Justice Department inquiry that Mr. Trump hopes will discredit the Mueller investigation, according to two American officials with knowledge of the call.

The White House restricted access to the call’s transcript to a small group of the president’s aides, one of the officials said, an unusual decision that is similar to the handling of a July call with the Ukrainian president that is at the heart of House Democrats’ impeachment inquiry into Mr. Trump. Like that call, the discussion with Prime Minister Scott Morrison of Australia shows the extent to which Mr. Trump sees the attorney general as a critical partner in his goal to show that the Mueller investigation had corrupt and partisan origins, and the extent that Mr. Trump sees the Justice Department inquiry as a potential way to gain leverage over America’s closest allies.

And like the call with the Ukrainian president, Volodymyr Zelensky, the discussion with Mr. Morrison shows the president using high-level diplomacy to advance his personal political interests.

President Trump initiated the discussion in recent weeks with Mr. Morrison explicitly for the purpose of requesting Australia’s help in the Justice Department review of the Russia investigation, according to the two people with knowledge of the discussion. Mr. Barr requested that Mr. Trump speak to Mr. Morrison, one of the people said. It came only weeks after Mr. Trump seemed to make military aid to Ukraine contingent on Mr. Zelensky doing him the “favor” of helping Mr. Barr with his work.

A Justice Department spokeswoman declined to comment. A White House spokesman did not immediately respond to a request for comment, nor did a spokesperson for the Australian prime minister.

In making the request, Mr. Trump was in effect asking the Australian government to investigate itself. The F.B.I.’s counterintelligence investigation into Russian interference in the 2016 election began after Australian officials told the bureau that the Russian government had made overtures to the Trump campaign about releasing political damaging information about Hillary Clinton.

Australian officials shared that information after its top official in Britain met in London in May 2016 with George Papadopoulos, a Trump campaign foreign policy adviser who told the Australian about the Russian dirt on Mrs. Clinton.

Mr. Papadopoulos also said that he had heard that the Russians had “thousands” of Mrs. Clinton’s emails from Joseph Mifsud, an academic. Mr. Mifsud, who was last seen working as a visiting professor in Rome, has disappeared. Trump allies, like the president’s personal lawyer Rudolph W. Giuliani, have put forth an unsubstantiated claim that Western intelligence agencies planted Mr. Mifsud to trap Mr. Papadopoulos.

Mr. Barr flew to Italy last week and met with Italian government officials on Friday. The Justice Department spokeswoman would not say whether he discussed the election inquiry in those meetings, but former Justice Department officials said that Mr. Barr would need to ask foreign countries for cooperation in turning over documents pertaining to the 2016 election.

Attorney General William P. Barr has held private meetings overseas with foreign intelligence officials seeking their help in a Justice Department inquiry that President Trump hopes will discredit U.S. intelligence agencies’ examination of Russian interference in the 2016 election, according to people familiar with the matter.

Barr’s personal involvement is likely to stoke further criticism from Democrats pursuing impeachment that he is helping the Trump administration use executive branch powers to augment investigations aimed primarily at the president’s adversaries.

But the high level Justice Department focus on intelligence operatives’ conduct will likely cheer Trump and other conservatives for whom “investigate the investigators” has become a rallying cry.

The direct involvement of the nation’s top law enforcement official shows the priority Barr places on the investigation being conducted by John Durham, the U.S. attorney in Connecticut, who has been assigned the sensitive task of reviewing U.S. intelligence work surrounding the 2016 election and its aftermath.

The attorney general’s active role also underscores the degree to which a nearly three-year old election still consumes significant resources and attention inside the federal government. Current and former intelligence and law enforcement officials expressed frustration and alarm Monday that the head of the Justice Department was taking such a direct role in re-examining what they view as conspiracy theories and baseless allegations of misconduct.

Barr has already made overtures to British intelligence officials, and last week the attorney general traveled to Italy, where he and Durham met senior Italian government officials and Barr asked the Italians to assist Durham, according to one person familiar with the matter. It was not Barr’s first trip to Italy to meet intelligence officials, the person said. The Trump administration has made similar requests of Australia, these people said.