Singers and longtime friends Demi Lovato and Nick Jonas Monday announced a new tour together, including a stop at Brooklyn's Barclays Center.

"North America! Excited to announce The Future Now Tour with Demi Lovato. RSVP if you're coming," tweeted Jonas, 23. The tour's official page, futurenowtour.com, crashed in less than an hour, as Jonas noted in a subsequent tweet, and it remained down as of Monday afternoon, though the tour's Facebook page remained live.

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The tour commences June 24 in Sunrise, Florida, and hits Brooklyn on July 8. The 44-date tour ends Sept. 17 at The Forum in Inglewood, California. Tickets for the Barclays show go on sale Nov. 7 at 10 a.m.

This marks the sixth time the former Disney stars and business partners will have toured together. "The key for us," Jonas said on "Good Morning America" Monday, "was about living in this moment [after] taking a step out individually over the last year and a half, two years, and growing with our fans -- and then saying if there's ever a time to do it, it's now."

Meanwhile, TMZ.com on Friday said Adam Lambert originally was to have been opening act on a Lovato tour, but that after agreeing on creative detailing, billing and financial arrangements, Lovato was persuaded by her manager to replace Lambert with Jonas, whom the manager also represents.

Lambert, 33, tweeted in response on Friday, "Aww I love you all very much. No beef tween Demi Lovato & Nick Jonas and me. Biz negotiations are complex -- why do we care about the rumors?" Lovato, 23, replied to his posting, writing, "Just goes to show how accurate TMZ really is . . . I [heart] you Adam Lambert [followed by kiss-blowing emoji].