Nick Lachey and Vanessa Minnillo Engaged!

Nick Lachey and Vanessa Minnillo are taking their relationship to the next level: They're getting hitched!

"We're excited and incredibly happy about our engagement and we look forward to a wonderful future together," the longtime couple announced in a joint statement.

Lachey, 36, popped the question to Minnillo, 29, on Thursday "near a beach" in California, with an Asscher-cut diamond with baguettes from Bader & Garrin, a source tells PEOPLE.

On Thursday afternoon, Lachey took to Twitter to write, "Hey all. If anyone's heard the rumors of my engagement, they are absolutely true! Vanessa and I couldn't be happier. Thanks for all the love."