Key had warned the Fiji government not to do anything "silly" following the arrest of six prominent Fijians last month. He also said Bainimarama had mouthed off about the forum.
"He knows that I'm Frank by name and frank by nature. And I know that he's a similarly plain-speaking Kiwi," Bainimarama said.
Bainimarama also expressed his gratitude to New Zealand for the assistance his country received after the damage caused by Cyclone Winston.
"Helping Fijians get back on their feet is something that we will never forget."
Key said the relationship between the two countries was "good, strong and stable".
He said he welcomed the Fijian PM's visit and was ready for "positive engagement" and "constructive conversation".
Labour foreign affairs spokesman David Shearer wants the Government to keep pushing Fijian officials for a better democracy.
Bainimarama's visit coincides with the Bledisloe Cup match this weekend.
He attended the Fiji Trade and Investment Symposium at Auckland's Stamford Plaza Hotel this morning.
Bainimarama smiled and appeared at ease as he met children at a Fijian kindergarten, Bula Kindergarten, in Mangere this morning.
He then visited Moana Pacific Fisheries in Mt Wellington accompanied by Shane Jones, ambassador for Pacific Economic Development.