He also hopes the couple will be allowed to enjoy impending parenthood in private.
"I am very happy for them, but I just only hope that they, but mainly Catherine, hopefully gets the necessary protection to allow her as a mother-to-be to enjoy the privacy that that comes with. I seriously hope that's going to be able to happen," he said.
While William is happily settled as a husband and father-to-be, Harry isn't planning to rush down the aisle just yet.
"I don't think you can ever be urged to settle down. If you find the right person and everything feels right, then it takes time, especially for myself and my brother.
"You ain't ever going to find someone, who's going to jump into the position that it would hold. Simple as that," said the 28-year-old.