New Zealand shouldn't be concerned that Australia appears to be edging ahead in securing a crucial free trade deal with Britain, a local expert says.

British Prime Minister Theresa May is set to open talks on a landmark FTA with Australia and will meet her Aussie counterpart, Malcolm Turnbull, at the G20 summit in China tomorrow, the Telegraph reported.

New Zealand International Business Forum executive director Stephen Jacobi said securing an FTA with the United Kingdom was crucial given the country's impending exit from the European Union, dubbed "Brexit".

"New Zealand would have a particularly strong interest in getting underway some sort of negotiation with Britain, bearing in mind that one third of our exports to the EU go to Britain," Jacobi said. "Obviously we would have an interest in developing these sorts of discussions."


But he said it wasn't a blow for New Zealand that Australia appeared to be making quicker progress.

"It's only because Theresa May is going to see Malcolm Turnbull at the G20," Jacobi said. "John Key's not there - he'll see her on another occasion."

A spokeswoman for Trade Minister Todd McClay said New Zealand was committed to working with both the EU and the UK.

McClay and Foreign Minister Murray McCully had both recently had "fruitful discussions with the UK on a post-Brexit relationship".

"We expect the Brexit process to take some time, so there won't be any changes to our trading relationship in the immediate future," the spokeswoman said.

"Meanwhile we will continue to work towards the opening of FTA negotiations with the EU and, in the future, we would be interested to negotiate some form of FTA with the UK once it is in a position to do so."

Jacobi said May's talks with Turnbull were just "exploratory discussions".

"They're not yet a negotiation," Jacobi said.

"At the moment Britain is simply not able to enter into a negotiation with Australia, New Zealand or anybody because it's still a member of the European Union. The authority still resides in Brussels."

He said it could be 10 years before Brexit actually happened.

The Telegraph also reported that New Zealand, Australia and Canada would be lending "expert negotiators" to Britain to help that country negotiate its EU exit.

McClay's spokeswoman said New Zealand had agreed to share "some expertise" with the UK on trade matters.

"A UK official will be here later this week, as part of a visit to Canberra and Wellington and a senior New Zealand official will visit the UK later this month to help them better understand how New Zealand structures its trade policies and how we organise and resource our trade negotiations."