Katie Holmes has joined Twitter.

The former 'Dawson's Creek' star signed up to the social networking site this morning (25.10.13), and has sent her first messages from the set of her new movie 'The Giver' in South Africa.

For her first tweet, the 34-year-old beauty re-tweeted a picture posted by one of the film's producers, Nikki Silver, which features her and the rest of the cast of the upcoming sci-fi movie - including country singer Taylor Swift.

In the picture, Katie looks jubilant in the snap as she wraps her arm around the 'I Knew You Were Trouble' hitmaker for a group shot.

In a subsequent message, the actress wrote: ''So happy to be on twitter!!!!!! Sending first tweets from South Africa!!!!! (sic)''

Katie - who has a four-year-old daughter, Suri, with ex-husband Tom Cruise - amassed thousands of followers in just a few hours, but she still has a long way to go before matching the 35 million fans who loyally follow her co-star Taylor, 23.

As well as Katie and Taylor, 'The Giver' boasts an all-star cast including Oscar-winning star Meryl Streep, Jeff Bridges and newcomer Brenton Thwaites.

The sci-fi film - based on a 1993 novel by Lois Lowry - is due for release next year.