Ardern spoke this morning at Lautoka Mosque as part of her trip to Fiji to remember Imam Hafiz Musa Patel, Ashraf Ali Razak and Ashraf Ali.
She also thanked the Fijian community for their response in the aftermath.
"I want to place on record our deep appreciation for the many messages of support and sympathy we received from Fiji following the March 15 attacks, it gave us strength to know that you stood in solidarity with us.
"But it was especially moving to receive those messages when you faced your own grief," she said.