New Zealand Prime Minister Jacinda Ardern has been questioned over comments made by her friend which suggested US President Donald Trump mistook her for Canadian Prime Minister Justin Trudeau's wife at the recent APEC conference.

In a television interview with New Zealand's TVNZ1's Breakfast on Monday, Ms Ardern clarified that someone observing the meeting "second hand" told her they thought Mr Trump had confused the two women.

New Zealand Prime Minister Jacinda Ardern was questioned over comments suggesting US President Donald Trump had confused her for another woman.

"Someone said they thought that had happened, but in all my interactions, Mr Trump didn't seem to have confused me when I interacted with him," Ms Ardern said.

"They observed what they believed to be mistaken identity; I didn't pick that up.