Some Namibians hope the birth of the Brangelina baby will signify a national holiday.

Half of Namibians voting in an informal radio survey believe the day Angelina Jolie gives birth should be declared a national holiday, an honour usually reserved for kings, queens and national heroes.

"We have a tie, it's 50-50," the DJ for popular local radio station Radio Wave announced after listeners were asked whether the Brangelina baby should be accorded the honour. She said voting was still going on.

Hollywood stars Jolie and Brad Pitt sparked an international media frenzy when they arrived in Namibia with her two adopted children to have their first child.

But while residents of the southern African country have so far been unfazed by the visit, local media is now getting into the act, with the daily Namib Times speculating that the baby might arrive at the weekend or early next week.

The couple have remained almost invisible in their beach resort in the tiny village of Langstrand on the country's desert coastline, shielded by tight security.

And Brad Pitt has sent a message to fans about the "imminent arrival" of his new baby.

The Hollywood star said the "newest addition to our family" was due any time now.

Pitt, 42, has shied away from the spotlight since Jolie, 30, became pregnant with his longed-for child.

But he sent an email to his fans at the Cannes Film Festival, where his new film, Babel, is premiering.

Directed by Alejandro Gonzalez Inarritu, Babel sees Pitt plays a husband and father trying to cope with a crisis on vacation in Morocco.

Australian actor Cate Blanchett plays Pitt's wife, and the film also stars Gael Garcia Bernal.

Pitt said he was sorry he could not make the event.

"I am tremendously proud of Babel and want to congratulate everyone involved for this great achievement."