Murray McCully (left) and Mohammad Javad Zarif. Photo: NZ Herald

New Zealand's trade with Iran could surpass pre-sanction levels and tap into "vast possibilities", Iran's Foreign Minister has said ahead of a meeting with Prime Minister John Key today.

Mohammad Javad Zarif also defended Iran's human rights record and ballistic missile testing.

"We continue to buy butter and milk products from you, but we are interested in going beyond that and engaging in long-term economic relations with New Zealand," Dr Zarif told RNZ this morning.

Iran's Foreign Minister said new trade possibilities included investment in petrochemical products, and high-tech areas such as geothermal, nanotechnology and biotechnology.

Trade was top of the agenda for a meeting between Foreign Minister Murray McCully and Dr Zarif yesterday, that was described as a "refresh"of the relationship between New Zealand and Iran.

The two men met in the Beehive yesterday after Dr Zarif arrived during his tour of six countries in Asia-Pacific. The tour is part of Iran's efforts to attract more investment and trade following the removal of sanctions after last year's nuclear deal.

Mr McCully said Dr Zarif's visit was the first by an Iranian Foreign Minister in 10 years and let the countries "refresh" their relationship. He said he had raised human rights issues after thanking Dr Zarif for the role he played in the nuclear deal.

"[I] encouraged Iran to use this opportunity to reset its relationship with the international community. It was in this spirit I raised New Zealand's concerns about the human rights situation in Iran."

The ministers signed off on an arrangement between the Export Credit Office and Export Guarantee Fund of Iran which Mr McCully said would help give exporters more confidence in the trading arrangements.

Iran was New Zealand's fifth largest trading partner in the 1980s before sanctions on Iran bit. The removal of most of those sanctions opens the way for trade again.

Dr Zarif would meet Mr Key today and speak at an event for the Institute of International Affairs before leaving for Australia.

But his visit coincides with growing international concern about Iran's ballistic missile testing after further tests last week and reports the missiles had Hebrew inscriptions saying "Israel should be wiped off the Earth". That has prompted calls for sanctions from Israel and condemnation from the United States.

Dr Zarif defended the missile testing as not in breach of the nuclear agreement, or against a Security Council resolution.

"Missiles are a means of defence that we require ... we have provided the best guarantee that Iran will never develop nuclear weapons, nor nuclear warheads."

Asked about the high number of executions in Iran, Dr Zarif said every country could improve its human rights record, but the executions were largely the result of a crack-down on drug trafficking.

"The problem in Iran is we are on the transit route of the largest number of drug traffickers in the world, we confiscate over 80 per cent of the entire opium that is confiscated in the world."

Labour Party leader Andrew Little said he did not have a problem about engaging with Iran as the "international thaw" was under way.

"That is not to say things such as putting anti-Israeli messages on missiles is ever acceptable. In the long run, Iran needs to know its acceptability to the rest of the world depends on its ability to live in peace with its neighbours."

On the eve of Dr Zarif's arrival, Yosef Livne, the Israeli NZ Ambassador, issued a "personal reflection" criticising the willingness of the international community to embrace Iran.

"Everyone seems to be bent on securing business and in the rush overlook some very serious concerns. While the world is on its way to Tehran, Iran has not changed its aggressive behaviour. Its involvement in the Syrian civil strife, its continued support for Hizbollah and just yesterday we received a renewed reminder."

Dr Zarif and his entourage travel to Australia tomorrow where talks with Foreign Minister Julie Bishop are tipped to centre on asylum seekers.

Dr Zarif is in Wellington to build bridges after the lifting of sanctions on Iran, but the operator of the plane he flew in on was still subject to sanctions.

Dr Zarif and his delegation arrived in Wellington on the Iranian Government's Airbus A340-300, operated by Meraj Air.

Although sanctions on most of Iran's air carriers were lifted mid-January, there are still sanctions on Meraj Air as well as Mehan Air because of suspected support for groups including Hezbollah and Bashar al-Assad's regime in Syria.

The A340 Dr Zarif arrived in was reportedly purchased out of Pakistan last September.

Both Meraj Air and Mehan Air have been criticised for sidestepping sanctions by channelling the purchases through intermediaries.

The first major deal the Iranian government signed off on in January was for 114 Airbus planes for its civilian carrier Iran Air. The deal was signed on President Hassan Rouhani's visit to Europe.

- By Claire Trevett of the New Zealand Herald