Ngati Toa hopes the public will take heart from its deal with the Rugby Union as it chases a Treaty deal to protect the Ka Mate haka.

The haka was composed by their famous chief Te Rauparaha, and Ngati Toa signed letters of agreement for a settlement last year.

A final arrangement is yet to be fully negotiated, but the settlement will recognise the haka's cultural significance to the iwi and its authorship.

Last year Prime Minister John Key said the haka's inclusion in a settlement would not result in any veto or royalty charges on ordinary New Zealanders but the Crown should hold discussions with the tribe over its commercial use.

This week the tribe signed a memorandum of understanding with the New Zealand Rugby Union.

Details are confidential but parties say it gives certainty of its use for the All Blacks and, in return, Ngati Toa have assurances the haka's use will be respectful.

Tribal negotiator Matiu Rei said there was a degree of negative public reaction after last year's Treaty milestone was reached, centred on commercial opportunities from which the tribe might benefit.

"They thought [the deal] was about greed and they wondered what our motives were. We were never just after the money, that was never our primary objective."

Protection of a cultural icon from inappropriate use was at the heart of the claim, he said.

"There's no doubt in our mind the haka Ka Mate is a taonga. It's a fabulous part of Maori composition, and so it deserves protection."

The "amicable" memorandum with the rugby union should give the Government confidence to press on with the settlement, Mr Rei said.

Ngati Toa took huge pride from All Blacks performing the haka, and the nation's best-known brand benefited from the authenticity an agreement with the tribe gave the team.

"I don't see why it can't be replicated and I hope the Prime Minister is looking at this. This can be fabulous for the country - I think there's a huge hang-up that doesn't need to exist."

A spokesman for Treaty Negotiations Minister Christopher Finlayson said a settlement deed could be completed within few months.