Denzel Washington has offered some advice to George and Amal Clooney about becoming parents to twins.

The 'Fences' star - who has twins Olivia and Malcolm, 25, as well as John, 32, and Katia, 29, with his wife Pauletta Washington - is thrilled to hear the couple are expecting twins but urged them to ''sleep now'' as they won't be sleeping once the little ones arrive.

He told Entertainment Tonight: ''Sleep now! Because you won't be sleeping then! Sleep now! I'm not talking to George, I'm talking to his wife. Sleep now!

''He's gonna need support, and not from an actor. It's going to be a real performance. He'll see, but it's beautiful. We have twins and they're grown now, but it's a miracle.''

Since news of their impending arrival broke, celebrities including George's pal Matt Damon have rushed to congratulate the couple.

He said: ''I was working with him last fall and he pulled me aside on set and I mean, I almost started crying. I was so happy for him. And I was like, 'How far along is she?' And he goes, 'Eight weeks.'''

And George's mother believes he will be a ''great'' dad.

She said: ''We are extremely happy for George and Amal, and I cannot imagine two people who would be better parents. I think he'll be great, and I think she'll be a great mom! ... We were with them and they told us together. We were all together, and it was lovely. It was just a personal moment.''

The news was confirmed last week when the couple's close friend Julie Chen made the announcement during her talk show.

She said: ''Congratulations are in order for George and Amal Clooney! 'The Talk' has confirmed that the 55-year-old superstar and his highly accomplished 39-year-old attorney wife are expecting twins. Now, what we did find out that no one else is reporting, is that the twins are due this June!''