President Barack Obama endorsed Hillary Clinton for president on Thursday, with reports that he plans to campaign with her next week.

“I know how hard this job can be. That’s why I know Hillary will be so good at it. I don’t think there’s ever been someone so qualified to hold this office,” he said in his endorsement video in which he also states “I’m with her.”

The endorsement follows a meeting Obama had with Democratic candidate Bernie Sanders this morning.

“Honored to have you with me, @POTUS. I’m fired up and ready to go!” Clinton tweeted on Thursday.

Her campaign sent out tweets to supporters earlier in the morning saying that Obama “is on Team Hillary.”

Obama waited to endorse in the race until after Clinton claimed the nomination on Tuesday. He had been reluctant to wade into the race as Clinton and Sanders battled in the Democratic primary.

After his meeting with the president, Sanders said that he would continue to campaign for the Washington DC primary on Tuesday, but he also said that he looked forward to meeting with Clinton to talk about ways to defeat Donald Trump, the presumptive Republican nominee. It was perhaps an indication that he is ready to wind down his campaign.

In the endorsement video, Obama said that he has “seen her judgment, I have seen her toughness. I have seen her commitment to our values up close.”

Trump responded on Twitter. “Obama just endorsed Crooked Hillary. He wants four more years of Obama—but nobody else does!”

Clinton’s response: “Delete your account.” A Twitter spokesman said that it was Clinton’s most retweeted tweet ever — more than 153,000 times.