Former Trump campaign chairman Paul Manafort and his associate Rick Gates fought in federal court Thursday to “alleviate” their GPS monitoring system, as well as the terms of their home confinement after both pleaded not guilty to 12 counts by a federal grand jury.

Manafort and Gates appeared before Federal Judge Amy Jackson on Thursday afternoon, after being indicted as part of special counsel Robert Mueller’s investigation into Russian meddling and potential collusion with Trump campaign officials in the 2016 presidential election.

Manafort appeared in court with his attorney Kevin Downing. Gates, who was previously represented by a public defender and just Wednesday brought on a team of white-collar attorneys Walter Mack and Shan Wu, appeared in court Thursday with Wu.

Thursday is the first time Fox News has learned of a “GPS monitoring system,” which both Manafort and Gates have been wearing since being taken into custody on Monday. While unconfirmed, a GPS monitoring system is typically an ankle bracelet, or something similar.

Both Manafort and Gates are working to alleviate the GPS tracker. Gates’ lawyer filed a motion Thursday, and Manafort’s legal team is expected to do the same later Thursday.

“As a U.S. citizen, Mr. Manafort only has U.S. passports in his name. Although it might be surprising to some, it is perfectly permissible to have more than one U.S. passport, as individuals who travel abroad extensively no doubt know. Mr. Manafort has strong family and community ties and does not pose a serious risk of flight,” Downing said.

Gates’ attorney asked the judge for an exception this weekend so that he could attend his children’s sports activities. After the government had no objection, Jackson allowed the exception.

rick gates

Rick Gates was charged with 12-counts by a federal grand jury as part of the special counsel probe. (AP)

But in an apparent reaction to Downing’s statements made outside the courthouse on Monday after the indictment, Jackson warned attorneys about talking to the media.

“This is a criminal trial, not a public relations campaign,” Jackson said Thursday. “I expect the lawyers in this case to do their talking in the courtroom, not on the courthouse steps.”

On Monday, Downing made a statement to the press saying that “President Trump was correct.”

“There is no evidence the Trump Campaign colluded with the Russian government,” Downing said, referencing Trump’s earlier tweets. “A claim that maintaining offshore accounts to bring all your funds into the United States, as a scheme to conceal from the United States government, is ridiculous.”

Manafort and Gates are expected back in court on Monday morning at 9:30 a.m. for a bond hearing. Currently, unsecured bond is set for Manafort at $10 million, and $5 million for Gates.

But Judge Jackson said she is “very concerned that an unsecured bond is not sufficient,” alluding to the possibility that a traditional bond will be set during Monday’s hearing.

Manafort and Gates have both turned over their passports to the FBI.

Manafort and Gates were the first charges in Mueller’s probe into Russian meddling and potential collusion with Trump campaign officials in the 2016 presidential election.

The special counsel’s office told Fox News that the counts include conspiracy against the United States, conspiracy to launder money, unregistered agent of a foreign principal, false and misleading Foreign Agent Registration (FARA) statements, false statements and seven counts of failure to file reports of foreign banks and financial accounts.

According to the indictment, reviewed by Fox News, between at least 2006 and 2015, Manafort and Gates acted as unregistered agents of the Government of Ukraine, the Party of Regions, a Ukrainian political party whose leader Victor Yanukovych was president from 2010 to 2014, and the Opposition Bloc. Manafort and Gates generated tens of millions of dollars in income as a result of their work in Ukraine.

The indictment says that Manafort and Gates laundered the money through scores of the United States and foreign corporations, partnerships and bank accounts in order to hide Ukraine payments from U.S. authorities.

More than $75 million flowed through offshore accounts. Manafort, alone, allegedly laundered more than $18 million which was used by the former Trump campaign chairman to buy property, goods, and services in the U.S. while concealing that income from the U.S. Treasury and the Justice Department.

Manafort’s legal team said that they would like the trial to begin in April 2018.

Fox News' Jake Gibson and Allie Raffa contributed to this report.