The All Blacks' first home Test series defeat by Ireland was "not acceptable", says New Zealand Rugby CEO Mark Robinson.

It was New Zealand's first series defeat on home soil in 27 years.

In a statement Robinson congratulated Ireland on a "well-deserved win" but said: "We all know there is a huge amount of work to do."

There have been questions over the future of New Zealand head coach Ian Foster, but Robinson said he would be involved in a review before the Rugby Championship that starts in August.

Robinson said: "Clearly the performance across the series for the All Blacks was not acceptable.

"Our focus now is to work with Ian and his team to understand thoroughly in advance of the Rugby Championship what is needed to improve performance and where to go from here. We will begin this work immediately."

Foster, who was appointed in 2019, refused to discuss his future after the defeat in Wellington.

"I just want to talk about the Test match," he said. "New Zealanders have probably got to realise that this was a very good Irish team.

"We've got to go and analyse that series deeply again. It was a series we had a number of disruptions to our original plans going into it, but we were able to build a number of parts of our game.

"There's a number of new people who were exposed to a very intense series for us, one we haven't had for a while. It's given a massive marker for this particular group about where we're at."

Ireland's 23-12 victory in the second Test in Dunedin was their first over the All Blacks in New Zealand.

Three-time world champions New Zealand begin the defence of their Rugby Championship title on 6 August against current world champions South Africa.