Joe Biden's two surviving children Hunter and Ashley Biden introduced their father moments before he accepted the Democratic nomination for president on Thursday.

Also joining Hunter and Ashley was Beau Biden, whose words from a past convention were added to the introduction. Beau Biden died in 2015 after a battle with brain cancer.

"We want to tell you what kind of president our dad will be. He will be tough and honest, caring and principled. He'll listen, be there when you need him. He'll tell you the truth even when you don't want to hear it. He'll never let you down,” Hunter and Ashley Biden said, trading lines.

Hunter Biden became a household name last year when word came that President Donald Trump called on Ukrainian President Volodymyr Zelensky to investigate Hunter Biden’s role with Burisma, an oil firm owned by a Ukrainian. Hunter Biden held a job with the company as his father served his second term as vice president.

As vice president, Joe Biden was among western leaders who called for the exodus of Ukrainian prosecutor Viktor Shokin.

Trump and the White House tried to claim that Biden's push to ouster the prosecutor was influenced by his son's role with Burisma, but both Republicans and Democrats on Capitol Hill in addition to other western nations joined in calling for the ouster of Shokin.

The controversy with Hunter Biden was a campaign issue early on during the primaries.

"My son did nothing wrong," Joe Biden said during an October debate. "I did nothing wrong. I carried out the policy of the United States government in rooting out corruption in Ukraine. And that's what we should be focusing on."