"We all want to see an end to this conflict. The actions of the US, Israel and Iran are affecting every country in the world and we are deeply concerned about the prospect of further escalation," he said.
The prime minister was facing questions about Iran, fuel prices and National's poll numbers at the weekly post-Cabinet media conference.
It follows an eventful week in politics, including the latest Taxpayers' Union/Curia poll put National slightly up but still below 30 percent.
Fuel prices have continued to surge, with no sign yet the US, Israel and Iran will stop fighting - US President Donald Trump instead threatening to take out civilian infrastructure and send the country to "hell".
Luxon earlier on Tuesday called Trump's comments "unhelpful". This afternoon he said the longer the conflict goes on, the more severe the impacts are - including for Kiwis. He said he was disappointed that Air New Zealand were having to make cuts to their flight schedule, saying he had been affected by the cuts.
He said everyone wants to see end to the conflict and was deeply concerned about further escalation.
Luxon did not want to engage in questions over the latest poll result, saying it was not a priority for New Zealanders: "The real poll that will matter will be November 7 - we've got plenty of time for election year, but for right here right now that's not want Kiwis want me focussed on."
"There's a lot of them [polls], as I said I'm very focused on doing my core job which is making sure we navigate this fuel crisis well".
The latest Taxpayers' Union-Curia poll earlier in the afternoon had National still under 30 percentage points, but with New Zealand First gaining nearly four points the coalition bloc could comfortably retain the government benches.
Asked how many National MPs he would be comfortable losing from Cabinet given the poll numbers, he said reporters "may be losing what is not a priority for New Zealanders right now".
"I appreciate there's a lot of interest in polls, as I said, I don't comment on them because there's a lot of them saying often quite different things."
Foreign Minister and NZ First leader Winston Peters is headed to the US this week to speak with that country's Secretary of State Marco Rubio, but Luxon refused to predict or prejudge what their discussion might involve.
"He's an experienced foreign minister, he's got a good rapport and relationship with Secretary Rubio, but he'll be representing our interests very well. Our message is very clear which is that escalating rhetoric, and escalating actions frankly at a time like this are not helpful.
"That escalation ends up hurting New Zealanders and so that's why we keep calling for restraint, we keep calling for a de-escalation and certainly whether that's in language or action it's important that happens."
He said officials were also passing on the severe impact the conflict was having on New Zealanders, but "all we can do as New Zealand is actually make sure we stand up for our values and we call that out".
Luxon also confirmed New Zealand did not have a position on the reports that the United States was behind the bombing of a primary school on the first day of strikes in Iran.
"I've seen those reports as well but ultimately it's not me as the arbiter sitting here in New Zealand judging that, it's up to the Americans to explain that," he said.
He said New Zealand was calling for international humanitarian law to be upheld, "and when we see strikes on civilian infrastructure and on civilians that is unacceptable", but repeated that was not for him or New Zealand to judge.
"We don't," he said, when asked if New Zealand had a position on the bombing. "As we've said before, that is an issue for the Americans to explain."
He also batted away questions about the government's domestic response to the fuel crisis, refusing to say whether more targeted groups might receive support.
"There's lots of businesses, lots of households that are doing it really tough," he said.
"All I'm saying very clearly is that we know rising fuel prices are putting immense pressure on New Zealand households and businesses, we get that, but I'm also being straight with New Zealanders - which I think they need me to be - which is actually saying we cannot alleviate that pressure on everyone."
He said that was "the big learning out of Covid, where money was sprayed around in a cash bazooka, untargeted, not timely, not temporary".
He referred to Monday's update on fuel supply levels: total stocks of about 62 days of petrol, 51 days of diesel, and 50 of aviation fuel.
"So there's enough storage in the country for that quantity to happen. And I know initially, you know, I think New Zealanders have been actually really good, I mean initially in that first week we saw a little bit of people consuming, you know, a little bit of stocktaking, but since then it's actually been very stable in terms of consumption data so it's been pretty good."
He then cut off a question about fuel storage being about two thirds full.
"Look, we're really comfortable," he said. "The key thing we've got to look for in phase 1 is making sure there's no disruption to future fuel supply shipments or orders and there hasn't been."
Air New Zealand's decision announced on Tuesday of cuts to flight schedules and increased ticket prices were "disappointing, but really they need to make commercial decisions, and that's really decisions for them".
"Obviously I've been a recipient of not being able to use the full schedule at the full time either, but the reality is they need to make commercial decisions based on what they're experiencing with respect to how they're navigating high prices for jet fuel."
Asked about comments from the Transport Minister Chris Bishop, and from Finance Minister Nicola Willis that fuel excise increases set down to come in from 1 January next year were unlikely, Luxon gave away no new information.
"Stalling that or deferring that will be probably the wisest course of action but [Bishop] will confirm that and talk through the options around that shortly," he said.
The minister had been "pretty clear" the phasing of the roads would need to be reconsidered "and how we are digesting and prioritising projects in that context, and I think that's just good practice to get into".
Luxon ended the briefing about 3.30pm to attend the swearing-in of MPs Mike Butterick and Cameron Brewer, who he named Ministers outside Cabinet in a reshuffle last Thursday which saw Bishop lose his roles as Leader of the House and National's campaign chair.
