New Zealand shares fell on Thursday while markets digested the easing tensions between Iran and the US, as well as the announcement of new US tariffs.

The S&P/NZX 50 Index fell 0.7% or 97.9 points to close at 13,659.79.

US President Donald Trump said on Wednesday that the killings linked to Iran's crackdown on nationwide protests appeared to be easing, and that he did not believe Tehran was planning large-scale executions of demonstrators, even as analysts and diplomats cautioned that a US military intervention could carry significant risks, according to a Wednesday Reuters report.

Trump on Wednesday imposed a 25% tariff on certain artificial intelligence chips, including Nvidia's H200 processor and a comparable chip from Advanced Micro Devices, the MI325X, under a new national security order issued by the White House, a separate Wednesday Reuters report said.

In domestic news, the lift in New Zealand's retail spending in the last few months of 2025 is expected to continue this year, according to a report by Westpac.

In corporate news, Ryman Healthcare (NZE:RYM, ASX:RYM) reported 375 occupation right agreements sales in the fiscal third quarter, down from 394 a year earlier.

AFT Pharmaceuticals (NZE:AFT, ASX:AFP) said it is on track to meet its fiscal 2026 operating earnings guidance of NZ$20 million to NZ$24 million.