Mariah Carey's twins have taken their first steps

He said: "They are taking steps and figuring it out, but I wouldn't say they are walking yet. I thought walking was like, one day you stand then you just start walking. I didn't know it was a process. There's a lot of falling. They take a few steps and then fall and go right back to crawling."

The pair are even in competition with his daughter taking more steps than her brother.

Nick added to People.com: "Roc can balance himself a lot better. He can stand and bounce without falling for a long time. But Monroe takes more steps than he does."

Since welcoming the twins last year Nick has suffered a number of health setbacks including blood clots and kidney failure, and he now tries to go no longer than a week without seeing his children.

The 'America's Got Talent' host added: "I try not to go seven days without seeing them. I'll be with them this weekend."