Attorney General Jeff Sessions has asked for 46 US attorneys who were nominated by President Obama to resign their posts, the Justice Department announced in a Friday statement – a number that would appear to include the nation's most prominent prosecutor.

It wasn't immediately clear whether the group included crusading Manhattan US attorney Preet Bharara, who met with then President-elect during the transition and says Trump asked him to keep his crime-fighting post.

But neither White House nor Justice Department officials were able to clarify the situation Friday evening.

Senator Charles Schumer (D-NY), who used to have Bharara on his staff and helped secure his appointment, came out with a Friday evening expressing concern.

'I'm troubled to learn of reports of requests for resignations from the remaining U.S. Attorneys, particularly that of Preet Bharara, after the President initiated a call to me in November and assured me he wanted Mr. Bharara to continue to serve as U.S. Attorney for the Southern District,' Schumer said.

Manhattan US Attorney Preet Bharara met with Donald Trump at Trump Tower in November. His name appears to have been included among those top federal prosecutors asked to resign

'While it's true that presidents from both parties made their own choices for U.S. Attorney positions across the country, they have always done so in an orderly fashion that doesn't put ongoing investigations at risk. They ask for letters of resignation but the attorneys are allowed to stay on the job until their successor is confirmed.

'By asking for the immediate resignation of every remaining U.S. Attorney before their replacements have been confirmed or even nominated, the President is interrupting ongoing cases and investigations and hindering the administration of justice.'

A law enforcement source told CNN the Justice Department announced the news before some prosecutors had been told they had to leave their positions.

Department spokesman Peter Carr told USA Today that Trump had phoned attorneys Dana Boente of the Eastern District of Virginia, who is the acting deputy US attorney general, and Rod Rosenstein, US attorney for the district of Maryland, to say 'that he has declined to accept their resignation, and they will remain in their current positions'.

Bharara met with Trump in Trump Tower in November and told reporters afterward he had decided to 'stay on.'

He is among a group of Obama-appointed holdovers who did not vacate their offices following the transition to the Trump administration.

A DOJ spokesperson asked for further guidance could not confirm information on the status of Bharara, but upon reviewing the wording of the statement relating to all Obama holdovers, said: 'It sounds as though that's the case.'

The US attorney's office in New York had no comment about the Justice Department's announcement.

As the top federal prosecutor in Manhattan, Bharara has helped bring down top political leaders in both parties. His jurisdiction also could interface with the Trump Organization, which is located in Manhattan.

He helped bring down New York Assembly Speaker Sheldon Silver, a Democrat, on corruption charges, and then prosecuted Senate minority leader Dean Skelos, a Republican.

Attorney General Jeff Sessions has asked 46 US attorneys to resign their posts

Bharara told reporters after meeting with Trump that he had been asked to 'stay on'

A White House spokesperson referred questions to the Justice Department.

His jurisdiction could have put him in a position to pursue the Trump administration.

On Wednesday, watchdog groups wrote Bharara ugring him to pursue potential violations by the Constitution's Emoluments clause, which prohibits federal officials from accepting gifts or payments from foreign governments, the Washington Post reported.

The statement released by the Justice Department made no mention of Bharara or any exceptions to those being asked to resign.

'As was the case in prior transitions, many of the United States Attorneys nominated by the previous administration already have left the Department of Justice,' said Justice Department spokeswoman Sarah Isgur-Flores in a statement.

'The Attorney General has now asked the remaining 46 presidentially appointed U.S. Attorneys to tender their resignations in order to ensure a uniform transition. Until the new U.S. Attorneys are confirmed, the dedicated career prosecutors in our U.S. Attorney's Offices will continue the great work of the Department in investigating, prosecuting, and deterring the most violent offenders,' she said.

Bharara told reporters in the Trump Tower lobby in November: 'The President-elect asked, presumably because he's a New Yorker and is aware of the great work that our office has done over the past seven years ... whether or not I'd be prepared to stay on' Bhrara said. 'I agreed.'

Trump had reached out to Senate Minority Leader Charles Schumer in advance of the meeting, and even asked him for Bharara's cell phone, the Daily News reported. Bharara previously worked for Schumer.

Many of the federal prosecutors who were nominated by Mr Obama have already left their positions.

But the 46 who stayed on in the first weeks of the Donald Trump administration have now been asked to leave 'in order to ensure a uniform transition,' Justice Department spokeswoman Sarah Isgur Flores said.

It is customary, though not automatic, for the country's 93 US attorneys to leave their positions once a new president is in office.

The Obama administration allowed political appointees of President George W Bush to serve until their replacement had been nominated and confirmed.

A new POTUS can do what he wants with US attorneys, but coming when it does, this smacks of Trump paranoia about "deep state" conspiracies. — Matthew Miller (@matthewamiller) March 10, 2017

The federal prosecutors are nominated by the president, generally upon the recommendation of a home-state senator.

One US attorney appointed by Bush, Rod Rosenstein of Maryland, remained on the job for the entire Obama administration and is the current nominee for deputy attorney general.

US attorneys are responsible for prosecuting federal crimes in the territories they oversee. They report to Justice Department leadership in Washington, and their priorities are expected to be in line with those of the attorney general.

Sessions submitted additional information to the Senate Judiciary Committee this week after it was revealed he did not disclose during his confirmation hearing that he had met with the Russian ambassador to the U.S. on two occasions.