New Zealand shares ended flat on Tuesday while most Asian stocks saw gains as investors hope for a US-Iran peace agreement.

The S&P/NZX 50 Index was little changed to close at 13,017.26.

Dialogue between the US and Iran is "still alive," even after the failed negotiations that took place in Islamabad, Pakistan, according to a Monday Reuters report, citing sources familiar with the matter.

Also, US ​President Donald Trump said on Monday that Iran "called this morning" and wants to make a deal, but he will not agree to an agreement that does not forbid Iran from having a nuclear weapon, according to a Monday Reuters report.

"The failed weekend talks did not produce a deal, but they also did not close the door on diplomacy, ​and that is enough for equities to keep pushing higher for now," said Charu Chanana, Saxo's ⁠chief investment strategist, as quoted by Reuters in a separate report.

In domestic news, the share of first home buyers' property purchases in New Zealand in the March quarter was over 27%, buoyed by lower house prices, reduced mortgage rates, and policy measures, Cotality said.

In corporate news, Winton Land (NZE:WIN, ASX:WTN) received conditional approval from the expert panel for the Ayrburn Screen Hub under the Fast-track Approvals Act, with the decision now subject to a 20 working day appeal period.

Westpac Banking (NZE:WBC, ASX:WBC) will boost credit provisions for customers in energy-intensive sectors due to the volatility and economic uncertainty created by the Middle East conflict.