New Zealand Prime Minister Chris Hipkins said on Tuesday he would attend the upcoming NATO summit in July, while Australia's leader said he was still considering whether to travel.
Both countries have a decades-long relationship with the North Atlantic Treaty Organization that has taken on greater importance following Russia's invasion of Ukraine.
Finland this month joined the now 31-member alliance in a historic policy shift, while neighbour Sweden has applied to do so.
Hipkins said he would seek to advance a trade agreement with the European Union while at the NATO summit, due to be held in the Lithuanian capital Vilnius in July.
"When overseas I will look to put trade front and centre in order to support our economic recovery," he said in a statement.
Australia and New Zealand both attended last year's summit in Madrid as non-member participants.
Local media previously reported Australian Prime Minister Anthony Albanese would not travel to the summit, but he said in a radio interview on Monday that no decision had been made.
"I haven't had a chance yet to talk to the NATO Secretary General," Albanese told state broadcaster ABC.
"I will give it consideration," he said. "I attended last year in Madrid and subject to logistical arrangements, then I would be very pleased to accept the invitation."
(Reporting by Alasdair Pal in Sydney; Edited by Jamie Freed)