Special counsel Jack Smith's opening brief appealing the dismissal of former President Donald Trump's classified documents case is due on Aug. 27, according to a briefing notice Thursday from the United States Court of Appeals for the Eleventh Circuit.

Smith last week filed an official notice of appeal after U.S. District Judge Aileen Cannon, in a surprise decision, dismissed Trump's classified documents case.

Cannon dismissed the case on the grounds that Smith's appointment as special counsel was unconstitutional because he was not appointed by the president or confirmed by Congress.

In a statement following the ruling, a spokesperson with the special counsel's office said, "The dismissal of the case deviates from the uniform conclusion of all previous courts to have considered the issue that the Attorney General is statutorily authorized to appoint a Special Counsel."

Based on the briefing schedule in the court's notice, Trump and his co-defendants' response to Smith's opening brief will be due around late September, and Smith's reply will be due in mid-October.

Trump pleaded not guilty last year to 40 criminal counts related to his handling of classified materials after leaving the White House, after prosecutors said he repeatedly refused to return hundreds of documents containing classified information and took steps to thwart the government's efforts to get the documents back.

Trump has denied all charges and denounced the probe as a political witch hunt.