A humid evening greeted Prime Minister Jacinda Ardern as she touched down in Singapore to start her first overseas trip in more than two years.

Ardern and a 12-strong trade and business delegation are spending this week in Singapore and Japan, where several agreements to boost food exports and develop sustainable energy are expected to be announced.

The main message is that New Zealand, having been isolated for much of the pandemic, is open for business and tourists.

Ardern, the trade delegation, and a contingent of Defence Force support crew and media flew on the RNZAF Boeing 757.

With fiance Clarke Gayford alongside her, Ardern and Trade and Export Growth Minister Damien O'Connor were met at the airport by Indranee Rajah, Singapore's Minister in the Prime Minister's office.

In coming days, Ardern will have one-on-one time with her Singaporean and Japanese counterparts, Prime Ministers Lee Hsien Loong and Fumio Kishida, to discuss China's influence in the Indo-Pacific, including its reported security deal with the Solomon Islands, as well as the Russian invasion of Ukraine.

Tomorrow she is a key speaker at a breakfast panel discussing the role of digital transformation, before her bilateral meeting with Prime Minister Lee.

"We'll share from our perspective that we are in an increasingly contested region. Some of the ways that we can ensure that there is resilience in our region is actually some of the economic relationships that exist in our part of the world," she said in a pre-trip interview.

She will then have a courtesy call with Singapore President Halimah Yacob before attending a gala dinner.

Trade with Singapore has surged in recent years and Singapore is now New Zealand's fifth biggest trading partner, right behind the fourth biggest, Japan, where Ardern will fly on Wednesday evening.

The only catch is Covid-19. If anyone tests positive for the virus - multiple tests are needed for travelling - they will have to isolate where they are, including Ardern.

But the Prime Minister said the risk of getting stuck was worth it to travel again and promote New Zealand exports on the world stage.

"It's the reality of travel today. Our view is that now's the time to get out and about, to support our exporters, so we're willing to take on board the risks.

"It's a chance to promote New Zealand to demonstrate that we're reconnecting, that we're back in business."