Jacinda Ardern has met with British Prime Minister Theresa May.

UK correspondent Emma Keeling told Kate Hawkesby she had a one on one chat with Theresa May, which included trade.

She says New Zealand had already been told it was a priority for a deal once Britain left the EU.

"But the newest news that we have had is that the EU has given the UK the okay to start preliminary talks. Not full on negotiation, but just approval."

The two are attending a Five Eyes with Australian Prime Minister Malcolm Turnbull and Canadian Prime Minister Justin Trudeau, where Russia is high on the agenda.

May said Russia has also been trying to distort the truth of what happened in chemical weapons attacks in Salisbury and in Syria.

"Its interference over the past year has included attacks on the public sector, media, telecommunications, and energy sectors," May said.

"They're using cyber as part of a wider effort to attack and undermine the international system."

Australian Prime Minister Malcolm Turnbull said illegal conduct from Russia cannot be tolerated.

"Whether it is a chemical attack in Syria, the use of a nerve agent on British soil, or the expanding cyber attacks across the internet ... these must be resisted, they must be protected, they must be identified," Mr Turnbull told the meeting.

Trudeau said the four nations, who along with the United States make up the Five Eyes security alliance, stood in solidarity with the UK.

Ardern said the four countries would work together on security and making sure the system of rules-based international law was maintained.

The fact New Zealand hasn't told any Russian diplomats to leave the country following the poisoning of a former Russian spy in England was met with ridicule by some, but Keeling says it has not caused any issues with the Brits.

"But Theresa May came out saying that Britain has a very good relationship with New Zealand and they are pleased with the response

- with content from NZ Newswire