The New Zealand prime minister has grounded herself during the COVID-19 pandemic, eschewing normal diplomacy and travel.

However, with the opening of New Zealand's borders, Ms Ardern has indicated she will travel in earnest during 2022, including trips to Australia, Europe, Asia, and the United States.

"Now we must continue to reconnect with the world and I look forward to supporting our businesses across a range of sectors, and seeing my political counterparts in person," she said.

Ms Ardern will meet with Singapore prime minister Lee Hsien Loong and president Halimah Yacob, and Japanese prime minister Fumio Kishida, marking the 70th anniversary of formal NZ-Japan diplomatic relations.

She is travelling on a NZ Defence Force plane with trade minister Damien O'Connor and 13 Kiwi business leaders from the dairy, food and beverage, technology, tourism and renewable energy sectors.

The delegation will make a number of business-oriented engagements, leaving New Zealand on April 18 and returning on April 24.

"This first trade mission is part of our wider plan to reconnect with the world following the devastation caused by the COVID-19 pandemic," Ms Ardern said.

Japan is New Zealand's fourth largest trading partner, with imports and exports totalling $NZ8.3 billion ($A7.6 billion) last year.

Singapore is the fifth, worth $NZ6.6 billion ($A6.1 billion).

Next month, Ms Ardern will also visit the US to give the commencement address at Harvard University.

She is expected to also visit Australia shortly after the federal election if there is a change of government.

Australian Associated Press