Kevin Jonas is officially a father of two!

The 28-year-old singer's wife, Danielle, gave birth to their second child, a precious baby girl named Valentina, on Thursday.

WATCH: Kevin and Danielle Jonas Expecting Second Child -- See the Cute Announcement!

"Thank you so much for all your well wishes Valentina is happy and healthy," Kevin tweeted Thursday evening. "I'm so in love."

Kevin's brother, Nick Jonas, was the first to confirm the news via Twitter, writing, "AHH! I'm an uncle again! Congrats to my brother and sister in law on the birth of their new beautiful baby girl. @kevinjonas @daniellejonas."

The "Chains" singer, who is currently in Hawaii, also took to Instagram to congratulate his brother with a sweet video message. "I just got the best news ever," he said in the clip. "My brother and his wife had their baby. I'm overjoyed!"

RELATED: Kevin Jonas and Wife Danielle Announce Baby No. 2 Is a Girl

Prior to the newborn's arrival, Kevin and Danielle, who are also parents to 2-year-old daughter Alena Rose, were giving updates from the hospital on social media. Kevin told his fans that for him, "waiting is the hardest part," while "Dani would probably say the contractions."

"Can't believe we're gonna have 2 baby's," he added.

PHOTOS: Stars and Their Gorgeous Children All Grown Up!

Meanwhile, Danielle posted a pic of Kevin eating a full meal as she was snacking on a cherry-flavored Italian Ice popsicle. "How is this fair?" she joked.

"Anytime now," another caption read.

Danielle and Kevin announced they were expecting in April with a sweet pic of the two snacking on junk food and reading the parenting self-help book, What to Expect When You're Expecting Again. "Prepping for baby number two! #babyjonas2," Kevin exclaimed at the time.

Congrats to the happy couple!

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