WASHINGTON (TIP): US President Barack Obama formally endorsed Hillary Clinton‘s White House bid on Thursday, June 9, and called for the Democratic Party to unite behind her after a protracted battle with Bernie Sanders for the party nomination.

Clinton, the presumptive Democratic nominee, said it “means the world” to her to have Obama’s support.

“It is absolutely a joy and an honor that President Obama and I over the years have gone from fierce competitors to true friends,” Clinton told Reuters in an interview.

“I know how hard this job can be. That’s why I know Hillary will be so good at it.” —@POTUShttps://t.co/GDhRYAVn0P

— Hillary Clinton (@HillaryClinton) June 9, 2016

Obama defeated Clinton in the 2008 Democratic primary and she went on to serve as secretary of state. Obama, who enjoys strong approval ratings after nearly eight years in office, will campaign with Clinton next week in Wisconsin, her campaign said.

“I don’t think there’s ever been someone so qualified to hold this office,” Obama said of Clinton in a video. “I’m with her. I am fired up, and I cannot wait to get out there and campaign for Hillary,” Obama said. Sanders, who met with Obama at the White House earlier on Thursday, said afterward he would work with Clinton to defeat Trump.

In his endorsement video, the president took time to say that Sanders had run “an incredible campaign,” and that he had shone “a spotlight on issues like economic inequality and the outsized influence of money in our politics.”

In fact, Obama said, those are messages the Democrats should embrace for the general election. And while Clinton and Sanders may have been rivals during the primary season, “they’re both patriots who love this country and they share a vision for the America that we all believe in.”

“This has been a hard-fought race,” Obama said. “I know some say these primaries have somehow left the Democratic Party more divided: Well, they said that eight years ago, as well.”

And just as Democrats’ victory in that election paved the way for significant national initiatives, Obama said he expects his party “won’t just win in November, we’ll build on the progress that we’ve made and we will win a brighter future for this country that we love.”

Although the declarations of Clinton’s presumptive victory were based on her delegate haul, Sanders is not technically eliminated from the race because he could theoretically sway the Democrats unbound “super” delegates to his side. Still, that would be a tough sell for the senator: Clinton won more primary contests, more of the popular vote and more regular pledged delegates.

The endorsement increases pressure on Sanders, a US senator from Vermont, to concede the race so the party can focus on campaigning against Donald Trump, the Republican presumptive nominee for the Nov. 8 election.