Territory and Municipal Services Minister Shane Rattenbury announced a tightening of bus advertising arrangements on Monday, saying he was moving to better reflect the government's own policy objectives, and the values of the Canberra community.

The government already prohibits political, religious, antisocial and tobacco advertising from appearing on the fleet.

Mr Rattenbury acknowledged only a small number of buses currently displayed such ads, but said the changes were forward-looking.

"At this point it's reasonably limited, but we're keen to make sure that we have clear guidelines ... that are consistent with community expectations and the government's objectives," he said.

"Something like junk food advertising is a perfect example of that.

"We are seeking to promote healthier diets, and obviously on buses, particularly where you've got a lot of school children travelling, we want to have messages on our own buses consistent with the sort of things we're talking about to kids through schools."

The policy will restrict alcohol advertising, but not prevent nightclubs or licensed venues from purchasing ads on the bus fleet.

Mr Rattenbury said he had taken the decision to restrict advertising for products or industries that are "either damaging to the health of the population or environment or that promote weapons".

Asked whether restricting advertising on fossil fuels was a form of censorship, Mr Rattenbury responded:

"The government's got clear objectives to reduce our use of fossil fuels," he said.

"We've just taken steps to divest from a range of fossil fuels, so this is quite consistent with that."

The move comes in the wake of a recent campaign to remove weapons advertising from the Canberra Airport.

That campaign said the ads by weapons manufacturers were distorting the image of the city presented to visitors.

"I think the same should be said for our ACTION buses as a reflection of our Canberra community," he said.

He said the government would be considering other means of restricting such advertising across other publicly-owned assets.

Reducing junk food advertising was one aim of the Towards Zero Growth campaign launched two years ago, which aims to curb obesity.

"It is our responsibility to ensure that the products and messages that we promote on our public buses are suitable and appropriate for the broader population and in line with the values of the Canberra community and government objectives," Mr Rattenbury said.