NZ, Ardern voted Aussies' favourites

Australians have voted Jacinda Ardern as their favourite world leader for the third straight year.

The New Zealand prime minister's popularity has soared to 91 percent in the 2021 Lowy Institute's annual poll of Australians' opinions.

Ms Ardern has topped all-comers in each of the three years she has appeared, and this year set a record level.

"More Australians have confidence in Prime Minister Ardern than in their own prime minister. It's a remarkable level of closeness," Lowy Institute foreign policy director Natasha Kassam told AAP.

Ms Ardern outranks even the benchmark set by Barack Obama, who scored 88 and 86 percent in a similar question - of admiration - when polled in 2014 and 2015.

"It's so rare to see a result with a nine in front of it. It's really very unusual," Ms Kassam said.

"Australians see Prime Minister Ardern as someone who is warm and empathetic and straightforward and perhaps who isn't as engaged in polarising politics.

"A lot of Australians see politicians here to be unproductive at times and see a difference when they look across the ditch.

"Australians have seen Prime Minister Ardern handle the Christchurch massacre and the Covid-19 pandemic. The way she has handled those crises have inspired a lot of confidence."

The question asked Australians to "indicate how much confidence you have in each leader to do the right thing regarding world affairs".

Of the 2448 surveyed, 63 percent said they had "a lot" of confidence, up from 52 percent last year, with 28 percent saying "some".

US President Joe Biden was second, on 69 percent, with German chancellor Angela Merkel and Australia's prime minister Scott Morrison joint third on 67 percent.

North Korean leader Kim Jong-un ranked last with five percent.

The poll also asked Australians to rank their degree of warmth, from 0 to 100, towards other countries.

NZ won with an average of 87 - the highest score on record.

"New Zealand was far ahead of the United States and the United Kingdom in terms of the country that is Australia considers to be its best friend in the world," Ms Kassam said.

"It's a remarkable warmth."

Runner-up to be Australia's best friend was the United Kingdom with 76, ahead of Japan on 73, Germany on 69 and the Pacific Island Forum on 66.

China was last among 20 options, polling just 32.