NEW YORK (CBSNewYork) — The Twitter war between Hillary Clinton and Donald Trump is heating up.

The presumptive Republican presidential nominee took a shot at his Democratic opponent after President Barack Obama endorsed the former secretary of state Thursday.

COMPLETE CAMPAIGN 2016 COVERAGE

“Obama just endorsed Crooked Hillary. He wants four more years of Obama – but nobody else does!” Trump tweeted.

But then the shot heard round the Twitter world happened.

“Delete your account,” Clinton’s campaign fired back at the billionaire.

According to Time political reporter Zeke Miller, that is Clinton’s most retweeted tweet ever.

Trump, of course, responded.

“How long did it take your staff of 823 people to think that up–and where are your 33,000 emails that you deleted?” Trump tweeted, referencing Clinton’s ongoing email scandal while she was secretary of state.

Not to be outdone, Republican National Committee chairman Reince Priebus decided to join the fun and took a shot at Clinton.

“If anyone knows how to use a delete key, it’s you,” Priebus tweeted at Clinton.