A male Sumatran tiger called Oz killed 43-year-old Samantha Kudeweh and another senior staff member.
Details of the incident have not been released.
City officials said on Monday, however, there was “no reason” to euthanise the tiger, which is vital to the zoo’s breeding programme.
“Although there is an inherent risk for zoo professionals who manage big cats like Oz, there is no wider ongoing risk,” said Mr Vervoort a Hamilton City Council general manager.
“This is our call, and the decision on Oz rested solely with us.”
Kudeweh, a mother of two who was married to a colleague, had more than 20 years of experience working in zoos and was second-in-charge at Hamilton Zoo.
Her family said she was a “passionate conservationist“.
The incident remains under investigation, though Mr Vervoort said it is believed the animal acted in line with his natural instincts.
Hamilton Zoo will remain closed until Thursday.