Bale has established himself as one of the most dangerous attacking players in football in recent seasons and has often been linked with rival clubs.
Speculation recently has claimed that Real Madrid will make a move for the Wales international next summer, while Barcelona are also mooted as admirers of Bale.
Speaking after Bale's impressive performance in Wednesday's 2-1 win over Liverpool, Villas-Boas admitted he would understand if the winger received offers.
However, Villas-Boas has moved to reiterate his stance that Bale will not be sold and he remains an integral part of Spurs' future.
Villas-Boas told the club's official website: "Like all of our key players, Gareth is on a long-term contract as we continue to build for the future and his progression will be of benefit to our team.
"He is an important part of our future and we have no intention of letting any of our top players go."
Bale is under contract at Spurs until 2016 and has previously spoken of a wish to play football abroad at some stage in his career.