A ban on bikies in gang colours entering clubs and pubs in Sydney's notorious Kings Cross could be extended to other NSW trouble spots.

NSW Police Commissioner Andrew Scipione didn't specify which areas might also be subject to a ban.

But he said he had been assured by Police Minister Michael Gallacher that police would have the government's backing if they wanted to take wider measures.

"The minister said to me if we need any assistance like this anywhere else, then I should bring a case to him and let me assure you that we will," Mr Scipione told reporters.

Mr Scipione said the ban, which was sought by Kings Cross police last September, would specifically address issues in the red-light district.

"It's not one size fits all," he said.

"So at this stage the request by police specifically related to events which had taken place in the Cross ... and the advice we've received today is that the bans that we've asked for will be certainly imposed in and around that Kings Cross area."

Premier Barry O'Farrell announced the ban on Thursday.

The government stepped in to adopt the ban after the police submission was rejected by the Office of Liquor, Gaming and Racing (OLGR).

The OLGR had proposed instead that hotel and club operators act voluntarily to refuse admission to uniformed bikies.

The Police Association of NSW (PANSW) said the OLGR decision was "stupid" and amounted to "pandering to the interests" of bikie gangs.

"And it has shown complete disregard for public safety," PANSW president Scott Weber said in a statement.

Mr Gallacher said banning uniformed bikies would show the gangs they could not take over an area.

"The history of outlaw motorcycle gangs is all about territory and all about individual gangs controlling the street in a particular area," Mr Gallacher said.

"The wearing of the colours is basically the display of a flag. It basically says we are here en masse and this is our territory, and we cannot have that."

Mr O'Farrell said the ban would be enforced under Liquor Act provisions prohibiting people from entering licensed premises while wearing outlaw motorcycle gang or organised crime gang clothing or accessories.

"People ought to be allowed to go out and have and enjoyable and peaceable night in a pub or a club without that venue being taken over by one gang or another," he said.