Prime Minister Jacinda Ardern has been accused of hiding away on Māori issues during a visit to King Tūheitia, while her Māori caucus admits it'll face competition if it doesn't deliver before the election.

Ardern was on Tuesday welcomed to Tūrangawaewae Marae in Ngāruawāhia for the Māori King's annual coronation commemoration, Koroneihana.

The ongoing occupation of Ihumātao, in South Auckland, has loomed over this year's celebrations.

The King has been acting as a mediator between protesters who oppose housing development by Fletcher Building and the iwi authority that has endorsed the deal.

The Government is not party to the talks and its position so far has been to let mana whenua involved find a resolution.

Speaking at Ngāruawāhia on Tuesday, Ardern emphasised the need to let the Kīngitanga lead.

"I've learnt that sometimes leadership means recognising when you need to create space for others," she said.

"I will be there for those hard conversations, I am there. But I will also recognise when the seat at the head of the table isn't necessarily me."

But opening the speeches, Māori Party President Che Wilson challenged Ardern's commitment to broader Māori issues.

"During the Christchurch massacre, you showed the courage that made us all proud … What I encourage you consider now is to show the courage again when it comes to Māori," he said.

"You asked us to keep you to account at Waitangi this year. But every big issue with regard to Māori, it appears that you hide away."

Asked about the comment afterwards, Ardern replied: "I heard that raised on the paepae but at the same time I was there to hear it."

"Where there are hard issues, be it Oranga Tamariki, be it issues around our prison population, be it Ihumātao, I will be there, I will have those conversations."

Ardern said she had discussed the situation at Ihumātao with King Tūheitia during a private meeting on Tuesday, but would not say whether he had suggested a resolution was close.

"That will be for the Kīngi," she said.

He will make his address at the marae on Wednesday.

Ihumātao occupation leader Pania Newton, who was not at Tūrangawaewae on Tuesday, said talks were still ongoing and no agreement had been reached.

Back in Wellington, the co-chair of Labour's Māori caucus, Willie Jackson, admitted the party would come under pressure from Wilson's Māori Party if it didn't do more deliver for Māori in the next six to eight months.

The Government needed to show it had made gains on employment, housing and health or it would face a challenge, Jackson said.

"The reality is they are always there …. We can't just come down here and eat our lunch," he said.

"Yes, there's pressure on the Māori caucus. Do we have to deliver? Yes. But we have a bit of time and I think we're on track."

But Jackson defended Ardern's decision not to visit Ihumātao.

The protesters have launched a petition calling for Ardern to visit and say they'll march on her electoral office in Mount Albert, Auckland, on Thursday to hand it over if she doesn't accept before then.

Ardern says she has no plan to do so.

"We're fixed on a process taking its course and of course we will look at possibilities of the Prime Minister going down there, but they seem to be wanting to call her out every day," Jackson said.

Ihumātao is thought to be one of the earliest places settled in Tamaki Makaurau and those occupying the land say the site is of historical and cultural significance.

Fletcher Building hopes to develop 480 homes on the site in Māngere and earthworks had begun in July when machinery was blocked by protesters.

They were issued with an eviction notice on July 23 and Ardern announced a halt to the development three days later, as tensions escalated.

The land was sold to the company in 2016 after being designated a Special Housing Area by Auckland Council. It has been the subject of controversy since.

Meanwhile, Ardern said she and the King had also discussed concerns about Oranga Tamariki.

The terms of reference for a Maori-led inquiry into the Ministry for Children were presented at Tūrangawaewae on Tuesday.

The review is one of four being carried out following the publication of a video of an attempted uplift of a six-day-old baby in May, and has been called for by Māori leadership.

The Whānau Ora Commissioning Agency held a second hui on the probe on Monday at the invitation of the Kīngitanga.

"The time has come for change and a solution that is for Māori, by Māori, with Māori given the escalating disquiet in this country by our people," Commissioning Agency chair Merepeka Raukawa-Tait said.

"The State is signalling through that choice that it can do better and values its own answers over ours – well that is not the truth."

The agency says the inquiry will broadly ask which parts of the system are working for tamariki and whānau, and which aren't.