Hillary Clinton is hitting back at President Donald Trump for having claimed at a recent rally — without providing any evidence — that she was the one who colluded with Russia during the 2016 presidential contest.

At a rally on Wednesday night in Erie, Pennsylvania, Trump directly accused Clinton of engaging in a conspiracy with Moscow to influence the race for the White House.

"There was collusion between Hillary, the Democrats and Russia," Trump said, just after his supporters had chanted "lock her up" about Clinton. "There was a lot of collusion with them and Russia and lots of other people."

Trump has discussed that theory publicly and on Twitter, but the charge amounted to a direct allegation that Clinton herself conspired with the Russian government to influence the election. He offered no evidence of his claim.

The idea prompted a swift Clinton comeback.

"Seriously, you asked Russia to hack me on national television," she tweeted Thursday afternoon.

Seriously, you asked Russia to hack me on national television. https://t.co/YPktJyQ7Gx — Hillary Clinton (@HillaryClinton) October 11, 2018

The tweet was apparently in reference to a July 2016 press conference in which Trump invited the Russians to "find" thousands of missing emails from a personal server Clinton had used when she was secretary of state.

"I will tell you this, Russia: If you’re listening, I hope you’re able to find the 30,000 emails that are missing," Trump said then.

Minutes after Clinton tweeted Thursday, Donald Trump Jr. fired back, claiming that Clinton's campaign and the Democratic National Committee had spent millions of dollars "working with foreign agents" to create a "fake dossier with them."

"You should really sit this one out," he told Clinton, adding that "every time you talk, we win."

Your campaign and the DNC spent over $12,000,000.00 working with foreign agents to creat a fake dossier with them... you should really sit this one out.



Then again, keep going. Every time you talk we win. We appreciate the support. https://t.co/sgU5zOwpwb — Donald Trump Jr. (@DonaldJTrumpJr) October 11, 2018

Trump Jr.’s tweet was referring to the fact that a law firm representing the Clinton campaign and the DNC helped fund opposition research that eventually became a controversial dossier, known as the Steele dossier, on then-candidate Trump.

The back-and-forth comes as special counsel Robert Mueller continues to investigate whether Trump and his campaign colluded with Russia or obstructed justice afterward.