President Trump took to Twitter to mock Hillary Clinton, calling on his 2016 election rival to "get on" with her life and run again in three years.

"Crooked Hillary Clinton is the worst (and biggest) loser of all time," Trump tweeted Saturday morning. "She just can’t stop, which is so good for the Republican Party. Hillary, get on with your life and give it another try in three years!"

Clinton has been on tour for several weeks to help promote her campaign memoir, What Happened, and has frequently been critical of the president.

This week, she questioned the legitimacy of Trump’s 2016 victory amid concerns about how the Russian meddled in the election process.

“I think there are lots of questions about [the election’s] legitimacy and we don’t have a method for contesting that in our system,” Clinton told Mother Jones in an interview published Friday. “That’s why I’ve long advocated for an independent commission to get to the bottom of what happened.”

The former secretary of state, who won the popular vote but not the Electoral College, also admitted that there is no way to challenge the election result.

Clinton has not stated a desire to run for political office again, but Trump has repeatedly said he hopes she does run in 2020.