Foster said the city's reaction to the protest had changed over time due to the bad behaviour from some of the protesters.
"I think people's views have hardened and I think everyone wants our streets and city back and we don't want to put up with some of the behaviours they have been exhibiting."
Foster would not be drawn on any information he had about the police action being taken today, saying those questions should be directed at police.
However, he did add that "it would be nice" if Wellingtonians had their "city and streets" back by this time tomorrow.
When deciding what action to take, he said police had to balance up a whole range of different factors including the number of people on site, their own resources and how interactions between them and protesters had been going.
He had been down to the protest area earlier this morning, but couldn't see much and suspected police wouldn't let people get too close to it.
But well-known political activist John Minto has spoken out about police using force and pepper spray on protesters saying it was a step too far and the latest police actions were "unnecessary or unhelpful".
"I just don't think it's helpful for the police to be pepper spraying people or going heavy on them. I just don't think it's necessary at all," he said.
Instead, he believed the protest should have been left to peter out once the concerns around mandates were addressed.
"The protest isn't providing any significant threat to the people of Wellington or to people generally.
"It's an embarrassment to the Government and the Government should be embarrassed because of broken promises."
Minto said there was widespread community sympathy for the protesters who were voicing a "widespread, genuine community concern" about the Government overstepping the mark and breaking a promise it gave in 2020 about mandates.
If the Government had addressed the burning issue about when mandates would be lifted and shown some basic respect from day one then the protest would not have escalated to this level, he said.
"Yes, there were conspiracy theorists there, but the majority of people were there with a genuine concern about the mandates and the Government still hasn't apologised, still hasn't met with them, still hasn't said sorry it hasn't worked out this way - just a bit of basic respect would have gone a long way," he said.
"I was pleased with the initial police reaction. I think they had been trying to engage and de-escalate, but what they are doing today goes against that."