Police have defended their actions during an early-morning raid at the Aboriginal Tent Embassy in Canberra.

More than 40 police, some with riot gear, surrounded a burnt-out shipping container while contractors worked to remove it.

The structure was damaged during a suspected arson attack last month.

Federal authorities had declared it a safety hazard.

ACT police operations commander Mandy Newton says the operation had been in planning for about a fortnight and was approved earlier this week.

"You're never sure whether or not you'll have 10 people, 20 people, 50 people or 100 people there at the time," Ms Newton said.

"We have to maintain safety for our police officers in having adequate police available if things escalate and there is some level of a breach of the peace taking place."