A federal appeals court on Wednesday night moved former Vice President Mike Pence closer to appearing before a grand jury investigating efforts to undo the results of the 2020 presidential election, rejecting a bid by former President Donald Trump's lawyers to block the testimony.It was not immediately clear what day Pence might appear before the grand jury, which for months has been investigating the events preceding the Jan. 6, 2021, insurrection at the U.S. Capitol and efforts by Trump and his allies to subvert the election outcome. But Pence's testimony, coming as he moves closer to entering the 2024 presidential race, would be a milestone moment in the investigation and would likely give prosecutors a key first-person account as they press forward with their inquiry.In the video player above: Mike Pence plans to comply with the subpoenaThe order from the three-judge panel of the U.S. Circuit Court of Appeals was sealed and none of the parties are mentioned by name in online court records. But the appeal in the sealed case was filed just days after a lower-court judge had directed Pence to testify over objections from the Trump team.A lawyer for Pence and a spokesman for Trump did not immediately return emails seeking comment, and a spokesman for the Justice Department special counsel leading the investigation declined to comment.Pence was subpoenaed to testify earlier this year, but lawyers for Trump objected, citing executive privilege concerns. A judge in March refused to block Trump's appearance, though he did side with the former vice president's constitutional claims that he could not be forced to answer questions about anything related to his role as presiding over the Senate's certification of votes on Jan. 6."We'll obey the law, we'll tell the truth," Pence said in an interview with CBS News's "Face the Nation" that aired Sunday. "And the story that I've been telling the American people all across the country, the story that I wrote in the pages of my memoir, that'll be the story I tell in that setting."Pence has spoken extensively about Trump's pressure campaign urging him to reject Biden's victory in the days leading up to Jan. 6, including in his book "So Help Me God." Pence, as vice president, had a ceremonial role overseeing Congress' counting of the Electoral College vote, but did not have the power to affect the results, despite Trump's contention otherwise.Pence has said that Trump endangered his family and everyone else who was at the Capitol that day and history will hold him "accountable."Video below: Former Vice President Mike Pence previously spoke publicly about the events of Jan. 6, 2021"For four years, we had a close working relationship. It did not end well," Pence wrote, summing up their time in the White House.The special counsel leading the investigation, Jack Smith, has cast a broad net in interviews and has sought the testimony of a long list of former Trump aides, including ex-White House counsel Pat Cipollone and former adviser Stephen Miller.Smith is separately investigating Trump over the potential mishandling of hundreds of classified documents at his Florida estate, Mar-a-Lago, as well as efforts to obstruct that probe.It is not clear when either of the special counsel's investigations will end or who, if anyone, will be charged.