Former US President Donald Trump pleaded not guilty on Thursday to federal conspiracy charges accusing him of plotting to subvert the will of voters and overturn his 2020 election loss.

Trump’s first hearing before US District Judge Tanya Chutkan, the federal judge who will be overseeing Trump’s case, is scheduled for August 28.

Before entering his plea, Trump answered basic questions from the judge and was informed of the charges against him and the potential penalties. The most serious charges call for up to 20 years in prison.

Trump spoke briefly to reporters at Reagan National Airport after leaving the D.C. District Court.

"This is a very sad day for America," he said before boarding his plane. "This is a persecution of a political opponent."

The former President appeared before a magistrate judge in Washington’s federal courthouse two days after he was indicted on four felony counts by special counsel Jack Smith.

The four counts with which Trump has been charged are: A conspiracy to defraud the United States "by using dishonesty, fraud and deceit to obstruct the nation’s process of collecting, counting, and certifying the results of the presidential election"; a conspiracy to impede the Jan. 6 congressional proceeding at which the collected results of the presidential election are counted and certified; a conspiracy against the right to vote and to have that vote counted; obstruction of, and attempt to obstruct and impede, the certification of the electoral vote.

Speaking after Trump’s indictment was made public on Tuesday, Smith said the assault on the US Capitol building on January 6, 2021 was "fueled by lies" by Trump.

"It was fueled by lies. Lies by the defendant, targeted at obstructing a bedrock function of the US government — the nation's process of collecting, counting and certifying the results of the presidential election."

"My office will seek a speedy trial so that our evidence can be tested in court and judged by a jury of citizens," he added.

Before taking off to the Washington court on Thursday, Trump took to social media to again criticize the case as politically motivated.

“I AM NOW GOING TO WASHINGTON, D.C., TO BE ARRESTED FOR HAVING CHALLENGED A CORRUPT, RIGGED, & STOLEN ELECTION. IT IS A GREAT HONOR, BECAUSE I AM BEING ARRESTED FOR YOU. MAKE AMERICA GREAT AGAIN!!!” he wrote on his Truth Social platform.

Smith was appointed by Attorney General Merrick Garland last November to oversee over two Justice Department investigations involving Trump: The investigation into efforts to overturn the results of the 2020 election and his handling of classified documents, for which Trump has already been indicted and pleaded not guilty.

Before the indictment in the classified documents probe, Manhattan District Attorney Alvin Bragg charged the former president on 34 counts of falsifying business records in March.