An outstanding Treaty settlement with Ngapuhi is set to be the elephant in the room, when political leaders converge on Waitangi over the next few days.

The Far North iwi is among dozens of groups yet to reach settlements with the Crown, dashing its hopes of settling all historic grievances by the end of last year.

Deputy Prime Minister Bill English says negotiations with a number of iwi and hapu are still rolling along but taking longer than expected.

"We've got plenty to do over the next year or two, but it is good to feel like we've got through a lot of hard ones like the Whanganui settlement, the Tuhoe settlement, and if we could get some progress on Ngapuhi, that will be great," he says.

But Labour leader Andrew Little says Treaty of Waitangi obligations will continue after all settlements are finalised.

"It's not like a sale and purchase document - we sign it, we do it, and that's it, we shove it in the bottom drawer and life goes on," he says.

"It's a living document that carries ongoing commitments and obligations."