New Zealand Prime Minister Jacinda Ardern, who was praised at home and abroad for her handling of the Christchurch mosques shooting last month, received her highest approval rating since taking office in a widely watched poll on Monday.

The 1 NEWS Colmar Brunton political survey showed 51 per cent of respondents said Ardern was their preferred prime minister, climbing seven percentage points from the last poll in February.

It is the first political survey since a lone gunman killed 50 Muslim worshippers at two mosques in Christchurch on March 15.

Ratings for Ardern's rival, opposition National Party leader Simon Bridges, dropped one percentage point to five per cent.

Party vote results also showed Ardern's Labour Party rising three percentage points to 48 per cent while the National's rating dropping to its lowest since September 2017, at 40 per cent.

"All I know is that I'm doing my job to the best of my ability," Ardern told 1 News when asked about the poll result.

Since coming to power in 2017, Ardern's coalition government has faced several challenges including weak business confidence, emboldened unions and a slowing economy. Her youth and global celebrity has also given critics doubt.

But the 38-year-old leader struck all the right notes in the hours after the Christchurch attack.

Ardern promptly labelled the mass killing as terrorism, and set about reassuring a nation that has been largely unscathed by the violence and fears that have afflicted other countries in the past two decades.

A picture of Ardern's wearing a head scarf and comforting families affected by the massacre went viral on the social media, and garnered praises from Muslims around the world, as well as leaders of other nations.

She also successfully passed a contentious gun law within a month of the shooting, which banned semi-automatic weapons.

Ardern burst into prominence after her coalition ended 10 years of National Party's centre right rule, promising more money for social services and by vowing to tighten foreign investment rules.

She rocketed to global celebrity as an inspiration for women after the unexpected election win, and she became only the second leader to give birth while in office since former prime minister Benazir Bhutto.

The poll was taken from April 6 to April 10, and has a margin of error of 3.1 per cent, the polling agency said.