"I anticipate making an announcement in that regard soon."
But Ardern wanted to make sure the Muslim community in Christchurch, as well as iwi, local government, the mayor of Christchurch, the police and other agencies, were consulted before announcing a date.
A national memorial would be a huge security and logistical operation, given the likely huge scale of the event.
Foreign leaders and dignitaries would likely be in attendance.
This could include members of the British Royal family. The Queen, the Duke and Duchess of Cambridge and The Duke and Duchess of Sussex and sent their condolences to the victims of the attack.
Many global leaders of the Muslim Community could be in attendance as well.
Ardern's comments this afternoon come after Kiwis across the country have held vigils in their local communities.
Close to 12,000 people gathered at the Basin Reserve in Wellington to pay their respects to those killed on Friday.
A vigil at the Central Auckland St Matthew's church will be held tonight and thousands are expected to come to a gathering in Aotea Square on Friday.
Vigils will also be held in Napier, Hastings, Tauranga, Nelson, Dunedin and Queenstown throughout the week.
More are planned in Australia as well, with Melbourne holding a vigil tonight and Canberra to hold one tomorrow.
Ardern said she was aware of the vigils.
"I have no doubt that these will continue – in fact, I encourage people to come together".