Roger Stone, a former adviser to U.S. President Donald Trump, leaves the Prettyman United States Courthouse after a hearing February 1, 2019 in Washington, DC.

President Donald Trump joined calls on Tuesday for a new trial for his friend Roger Stone as a group of federal judges prepared to hold an emergency meeting on concerns of political pressure on the judiciary.

Trump's tweets of a Fox News commentator's remarks that a new trial is warranted for the Republican operative came hours before the judge in his case said on a conference call that Stone's sentencing will proceed as scheduled Thursday in federal court in Washington.

But Judge Amy Berman Jackson said she would postpone imposing the terms of that sentencing pending her decision on Stone's request for a new trial.

The tweets also came less than a week after Attorney General William Barr said Trump's tweeting about pending federal cases such as Stone's was making it "impossible" for Barr to do his job.

A group of more than 1,000 former Justice Department employees on Sunday called on Barr to resign. The former employees criticized Barr for his decision to recommend a lower prison sentence for Stone than what the trial prosecutors had first recommended last week.

Trump used his Twitter feed to harshly criticize the first suggested prison term for Stone, of seven to nine years, hours after the recommendation was made

. Four Justice Department prosecutors quit the Stone case after Barr sharply reduced their sentencing recommendation, with one of those prosecutors resigning altogether from the DOJ.

Stone was convicted in November of lying to Congress about his contacts with WikiLeaks during the 2016 presidential election and of witness tampering.

Last week, it was revealed that the jury forewoman in his case had a number of social media posts critical of Trump, and retweeted another user's posts commenting on Stone's arrest in early 2019.