As British Prime Minister Theresa May took time out from Brexit turmoil on Monday (local time) to meet with her Kiwi counterpart, Jacinda Ardern, at 10 Downing Street, officials from their two countries signed a "mutual recognition agreement".

Australia and the United Kingdom signed a similar deal over the weekend, intended to serve as a stopgap to give exporters the assurance regulatory requirements won't change post-Brexit while free trade deals are hammered out.

"They help to ensure New Zealand exporters will not be worse off in the immediate aftermath of Brexit and there will be a continuity of the existing rules," Ms Ardern said afterwards.

During their hour-long meeting, which Ms Ardern described as "warm", the pair also reaffirmed plans to launch free-trade talks after Brexit.

While trade between New Zealand and Britain was only about $NZ2.9 billion in 2017, the UK was the third largest source of foreign investment into New Zealand and a significant market for agricultural products.

Britain had only signed one of the 36 similar deals it was working on by last week, but International Trade Secretary Liam Fox has said he is confident about getting the most significant agreements over the line before the UK separates from the EU in late March.

Mrs May's meeting with Ms Ardern in London ahead of the World Economic Forum in Davos came as the British PM sought to break a parliamentary deadlock over the terms of Brexit after her original plan was overwhelmingly voted down last week.

While Ms Ardern praised Mrs May as "a woman of remarkable resilience" during an interview with the BBC before the meeting, she said a no-deal Brexit would be "very, very difficult".

Australian Associated Press