Mallard replied by saying he believes a wall may be needed.
I think we will have too have a wall. Not for general perimeter security but with gates that close when we get alerts to groups similar to these protestors. I love the openness and accessibility of our House and grounds. I want to retain that but have a way of keeping people safe
"I think we will have too [sic] have a wall. Not for general perimeter security but with gates that close when we get alerts to groups similar to these protestors.
"I love the openness and accessibility of our House and grounds. I want to retain that but have a way of keeping people safe," he wrote.
In a statement later, Mallard said Parliament's grounds will be "closed until further notice".
He confirmed that recovering plan for the grounds has been created and includes working alongside mana whenua and coordinating offers of assistance from volunteer groups.
On Wednesday evening, a community clean-up is being organised to clear out rubbish and other waste. Volunteers can sign up for the effort here and those wanting to donate money can contribute via the big clean up's Givealittle page.
Mallard has also asked members of the public to stay away from Parliament grounds until further notice.
"Due to assessments of the grounds' condition that must take place before that work can begin, and for health, safety, and sanitary reasons, I ask that all members of the public please stay away till advised otherwise."
He thanked emergency service, Parliament and health staff for the effort to provide safety during these past three weeks and coming weeks.
"I'd like to take this opportunity to thank the Police, Parliamentary Security, Buildings and Facilities, Health and Safety teams and all other staff for their continued efforts to keep everyone at Parliament and the surrounding areas safe.
"Their resilience and understanding, along with all of you who have been affected by this protest must be acknowledged and thanks given for everyone's hard work and messages of support," he said.
More information on the recovery plan will be released once it becomes available.
"We will restore our beautiful grounds and I will keep you informed of developments."