Former US Secretary of State and Democratic presidential nominee Hillary Clinton spoke to the Democratic National Convention on Wednesday, calling for "overwhelming" votes for former Vice President Joe Biden so "Trump can’t sneak or steal his way to victory."

In the comments broadcast during the virtual convention, Clinton said she wishes Trump "knew how to be a president" and expressed bitterness over her loss to him in 2016.

"After the last election, I said, 'We owe Donald Trump an open mind and the chance to lead.' I really meant it. Every president deserves that. I wish Donald Trump had been a better president. Because America needs a better president than this,” she said.

“For four years, people have said to me, ‘I didn’t realize how dangerous he was.’ ‘I wish I could go back and do it over.’ ‘I should have voted,’” Clinton continued. “This can’t be another woulda-coulda-shoulda election."

Clinton urged Democrats to request their mail-in ballots now, vote early and to get involved.

Pointing to Trump’s 2016 sales pitch to voters: “What do you have to lose?” she added, “Now we know: our health, our jobs, even our lives. Our leadership in the world and, yes, our post office.”

Clinton warned that if Trump is re-elected, “things will get even worse” and lamented her loss in 2016.

“Remember: Joe and Kamala can win 3 million more votes and still lose. Take it from me,” she said. “We need numbers so overwhelming Trump can’t sneak or steal his way to victory. “

Since losing the 2016 presidential election to Trump, Clinton has continued to criticize him. In one incident, she warned that Trump “is a clear and present danger to America” and said she is "convinced" that his associates worked secretly with Russia to defeat her bid for presidency.

Previously, Clinton ripped Trump over his decision not to recertify the nuclear deal with Iran, saying his threat to pull out of the accord is "dangerous" and suggesting he is undermining the validity of the United States' promises to other nations.