Donald Trump has vowed to commute the sentence of prisoner Ross Ulbricht who he said was convicted on political grounds.

During a speech at the Libertarian National Convention in Washington DC on Saturday, Trump also promised to pardon all of the January 6 prisoners, whom he called “hostages.”

“It will be my honour to pardon the peaceful 6 January protesters, or as I often call them, the hostages. They’re hostages.”

“There has never been a group of people treated so harshly or unfairly in our country’s history. This abuse will be rectified and it will be rectified quickly.”

Infowars.com reports: The promise was greeted with cheers by the audience. Trump continued with a further promise to ensure Ross Ulbricht, the founder of dark web marketplace Silk Road, is released from prison.

“And if you vote for me, on day one I will commute the sentence of Ross Ulbricht, to a sentence of time served.”

After the crowd’s chants of “Free Ross” had died down, Trump added, “He’s already served eleven years. We’re going to get him home.”

Ulbricht was sentence to life imprisonment without the possibility of parole in 2015.

Trump is the first president to address the Libertarian National Convention. No current or former president in the modern era has ever addressed a convention for a party other than the Democrats or the Republicans.

Trump faced a crowd that was unfriendly at times, despite efforts by officials from the Libertarian Party to avoid a spectacle. The crowd, numbering around a thousand, booed loudly when Trump suggested they nominate him for president.

“Maybe you don’t want to win. Only do that if you want to win,” Trump then quipped.

“If you want to lose, don’t do that. Keep getting three per cent every four years.”