Josh Brolin is set to become a father for the fourth time.

The 'Avengers: Endgame' star and his wife Kathryn Brolin are expecting their second child together, which will mark the fourth child for Josh, who already has two adult children - Eden, 26, and Trevor, 32 - with his first wife, Alice Adair.

Kathryn - who also has 19-month-old daughter Westlyn with Josh - confirmed the news on social media on Tuesday, writing: ''The Brolin's are a growin' !! Our little December babe is on the way.... (sic)''

As of the time of writing, Josh, 52, is yet to comment on the pregnancy announcement.

The happy news comes after the couple - who married in September 2016 - welcomed their daughter in November 2018.

At the time of Westlyn's birth, Josh wrote on social media: ''Mama Kathryn was stellar during this miracle birth and Bean is a flawless gem through and through. We are blessed to the core and appreciate so much the love and support during this pregnancy from ALL who have partaken in our journey, directly and/or indirectly. (sic)''

Whilst Kathryn added: ''Our family's newest (and tiniest) member. Nothing compares to this... nothing. My heart is totally different forever. @joshbrolin thanks for this little life of ours. (sic)''

Meanwhile, the 'Deadpool 2' star previously said he was feeling ''appropriately nervous'' about becoming a dad again ahead of his daughter Westlyn's birth, though he was thrilled about the new arrival because he loves the company of youngsters.

He said: ''I'm always excited about kids. I prefer being around kids. You know, they have the imagination. They're fun.

''I've heard other people be like, 'Kid's sitting there, he's staring at nothing, he's slobbering, like, what's the point?' The point is to sit there and slobber with him. That's the point.''