The celebrations today mark 174 years since the Treaty was signed.
Mana party leader Hone Harawira was among several who paid tribute to the former South African leader Nelson Mandela.
"After 27 years in jail he had a smile on his face and love in his heart....that's bigger than I could ever be."
Mr Mandela was also remembered by the Maori Council's Maanu Paul.
Following the dawn service at Waitangi, Mr Key underlined his Government's record on advancing Treaty settlements and offered an incentive to his Ngapuhi hosts to close the northern iwi's own deal with the Crown.
Addressing Maori leaders and Crown representatives, Mr Key said he was "proud to stand by our record on Treaty settlements" which had been "accelerated under this Government".
He paid tribute to coalition partners the Maori Party for their role in helping Maori succeed in areas including Treaty settlements.
His Government came into office with the aim to secure "just and durable Treaty settlements by 2014".
"That date was not a deadline but a best endeavours goal."
He pointed out the Government had in the last five years signed 41 of the 67 settlements to date.
"More deeds of settlement will be signed and more Treaty legislation passed before the year is out," he said.
Mr Key pointed out that Northland needed economic stimulus which the Government was addressing by encouraging minerals exploration, investment in agribusiness and improving transport links.
"However, the biggest injection will come when all iwi here willing and able to settle do so."
Iwi would be financially empowered with several hundred million dollars injected into the local economy, he said.
"My challenge to all Ngapuhi today is this: put aside your differences - the Crown is ready and willing to negotiate with whoever you choose as your representatives."
Mr Key said he was keen to see a deal struck this year.
"If that can be done I am prepared to look at some form of payment on account to incentivise people to act in a positive and progressive manner."