Police and protesters faced off as trucks and forklift drivers arrived with concrete blocks and began installing concrete barricades in eight surrounding streets in Wellington from 3am today.
Ardern told RNZ's Morning Report programme today while she didn't always understand or agree with every decision the police made, they would always have her support.
"I fully support the police. I won't always agree with every decision, but they have my support."
She said the disruption caused by the protest had been "extraordinary" and told those in attendance their point had been made and it was time for them to go home.
"The protesters have had their say, it is time they go home and now obviously the police are taking action to ensure it doesn't grow and to ensure that the disruption, or where people are behaving illegally, that that is addressed."
She said the Government and a "significant majority" of New Zealanders had been "extremely distressed" by the events in Wellington but noted the "important separation" between the police and Government.
"The law is very clear on this, and rightly so: Government cannot and should not ever be able to instruct the police as to how they enforce the law or when they enforce the law."
Ardern said this morning's police action was intended to prevent the occupation from growing larger and that she had been briefed by Police Commissioner Andrew Coster on what to expect once she arrived at Parliament.
"I think the message that's being sent here is that the police are forming, essentially a barricade around the edges of the protest.
"Ultimately, all of this would be resolved if simply people went home."
She said while the arrival of the convoy had been well signalled, she believed both police and the Government would want to review how they had prepared for the protesters' arrival at Parliament.
"I do think that the police themselves will want to go back, and certainly we will want to go back and look at what was known and whether the right preparations were put in place," she said.
"The decisions around how that is then responded to, ultimately does sit with the police at an operational level and those who have the ability to ensure the security of the grounds.
"Obviously we'll want to go back and look whether or not the right decisions were taken at the right time to ensure that it could be a peaceful protest, rather than what has become illegal activity."
