Acting Prime Minister Winston Peters has again called for calm and diplomacy following Iranian missile strikes on bases housing United States troops in Iraq, but confirmed New Zealand's base in the country was not hit.

United States officials have confirmed more than a dozen surface-to-surface missiles had been fired at two Iraqi military bases, with Iranian state television describing it as a revenge attack over the killing of top military commander Qassem Soleimani in an air strike by the United States.

Details of damage or injuries were not immediately available.

The NZDF was earlier today investigating claims New Zealand's base in Iraq had been hit, but in a statement in the afternoon, Deputy Peters said the missles had not targetted the camp.

"The Government has been informed that all New Zealand personnel are as safe as they can be in these developing circumstances," he said.

"The Government is working actively with our partners through military and diplomatic channels, and we continue to keep the security situation under close review, including implications for our personnel."

New Zealand currently has 45 Defence Force personnel stationed at Camp Taji, near the city, where they have trained Iraqi soldiers since 2015. Five more personnel are based in Baghdad.

The Government last year announced the mission would be withdrawing by June, 2020.

But concerns have been raised about the safety of New Zealand troops and that they could get caught up in Iranian strikes amid rising tension and rhetoric following Soleimani's killing.

New Zealand Defence Minister Ron Mark learned of the attack on US bases from media on Wednesday, with the news breaking as he spoke to reporters.

He declined to comment until he had been briefed.

Minutes earlier, Mark said while there were concerns about the situation, there were still no plans to immediately withdraw troops.

Asked if the Government would consider moving forward the end date, Mark said New Zealand would be assessing the situation and talking to other Coalition countries in Iraq.

"This is a case of coolly, calmly assessing the situation," he said.

That followed a Government announcement on Monday that New Zealand's training mission would be put on pause while personnel focused on defending their base.

Former Defence Minister Wayne Mapp said while he believed the prospect of all-out war between Iran and the United States was still unlikely, the latest round of strikes would fundamentally change the situation for New Zealand.

Mapp said while New Zealand was unlikely to pull out immediately, the end date was now very likely to move.

"I would actually use the word inevitable. I think it's inevitable that we will pull out. The only question is when," he said.