Former Trump campaign aide Sam Nunberg, left, arrives at the U.S. District Courthouse to appear before a grand jury, Friday, March 9, 2018 in Washington. Nunberg had insisted in a series of defiant interviews earlier in the week that he intended to defy a subpoena issued by special counsel Robert Mueller's office, which is investigating potential coordination between Russia and the Trump campaign. (AP Photo/J. Scott Applewhite)

WASHINGTON | A former Trump campaign aide arrived Friday at the federal courthouse in Washington for a scheduled grand jury appearance days after he defiantly insisted in a series of news interviews that he intended to defy a subpoena in special counsel Robert Mueller’s Russia investigation.

Sam Nunberg did not respond to reporters’ questions as he entered court shortly after 9 a.m.

Nunberg on Monday had balked at complying with a subpoena that sought his appearance before a grand jury as well as correspondence with multiple other campaign officials.

But later that night, Nunberg told The Associated Press that he had relented and would wind up complying after all. He said he had worked for hours to produce the thousands of emails and other communications requested by Mueller, who is investigating whether the Trump campaign improperly coordinated with Russia during the 2016 presidential election.

“I thought it was a teachable moment,” he said of his 24 hours in the limelight.

So far, 19 people and three companies have been charged in Mueller’s investigation. Among them are Trump’s former campaign chairman and the former White House national security adviser. Five people have pleaded guilty.

Associated Press writer Jill Colvin contributed to this report.