Nick Cannon is planning something "special and unique" to celebrate his children's birthday.

The 31-year-old America's Got Talent host and his wife Mariah Carey welcomed fraternal twins Moroccan and Monroe into the family last year.

The twins' birthday is coming up on April 30 and Nick wants to celebrate lavishly.

"We're going away," Nick told People magazine. "We're taking a break. It's going to be exciting. We're doing something special and something unique."

Nick is in awe at how fast his son and daughter are growing up.

"It's amazing. It goes by so fast," Nick said.

The twins are maturing quickly and Nick is becoming anxious as they approach toddlerhood.

"They're trying to walk and I'm nervous because they're at that age when anything can happen," Nick explained.

"My son has this thing where he loves banging his head and crushing stuff. Something new is happening every day."

The presenter suffered mild kidney failure and spent time in hospital over the Christmas holidays. He was later diagnosed with autoimmune disease lupus nephritis.

Nick is now in good form.

"I feel better than I've ever been," he gushed. "I'm in the best shape that I've ever been in."