'Onions on top': Jacinda Ardern, Scott Morrison make hilarious pact on Bunnings sausage sizzles at ASEAN

Jacinda Ardern and Scott Morrison have finally met face-to-face, and they've issued an important joint statement on sausage sizzle protocol.

The two Prime Ministers met for a bilateral at the East Asian Summit (ASEAN) in Singapore on Wednesday (local time).

Ms Ardern had promised to raise the issue of the deportation of Kiwis at the meeting, but the conversation first turned to a recent health and safety issue that has affected both Australia and New Zealand.

Hardware chain Bunnings has announced that from now on, all on-site sausage sizzles should abide by a controversial new rule: onions should be placed underneath sausages to prevent them from falling out of the bread and creating a slip hazard.

Ms Ardern was the first to broach the subject, calling it "the most pressing international or trans-Tasman news of the day".

Mr Morrison was less familiar with the onion saga, saying he'd had to ask a reporter to repeat their question about it at a press conference earlier in the day.

"I think we should make a joint commitment that on our watches, the Bunnings sausage sizzle shall continue," said Ms Ardern.

"I agree, I agree," said Mr Morrison. "Onions on top, or underneath, however you like."

"Just onions, they need to be available," clarified Ms Ardern. "So that's resolved!"

The bilateral meeting then continued on to more serious matters, with Mr Morrison thanking New Zealand for our "ongoing commitment" to the wars in Iraq and Afghanistan.

"Our timetables are very aligned now - and that's the usual thing between Australia and New Zealand," he said.

"But the other one we share greatly is our shared commitment to the Pacific, and I think in so many ways New Zealand has demonstrated the family approach to how we should all operate in the Pacific.

"We are seeking to take a similar approach, obviously on a larger scale, and I think it would be good to talk about how we can align those two initiatives, because we have the same deep commitment and family commitment to the region."

Ms Ardern said New Zealand has "no closer relationship and no friendlier rival" than Australia.

"So much we have in common - good groundwork that's already being done, but of course so much we can do together as well."

Speaking to media after the meeting, Ms Ardern said on the issue of deportation she didn't discuss specific cases with Mr Morrison but did mention cases where New Zealand citizens have been deported from Australia despite never having lived in New Zealand.

"He acknowledged that and there is discretion in the system, but for me it was important to make the point."

The change to Australia's migration law three years ago was a point of contention between Ms Ardern and the previous Prime Minister Malcolm Turnbull.

"When you have a policy like this, it will give rise to certain situations where it may not make sense, at least not from New Zealand's perspective in particular," Ms Ardern told media.

"We will keep raising those examples, those particular cases, because in our view there are situations where it's just not appropriate for those individuals to be deported."

She said the "depth of relationship" between the two countries means New Zealand can comfortably raise such disputes when they arise.

Ms Ardern said the two leaders didn't speak about Nauru in their 30-minute meeting, but said she intends to raise the subject with Mr Morrison at some point between now and the APEC summit later in the week.

Earlier in their meeting talk had turned to Mr Morrison's travels in New Zealand.

"I was advocating for Waiheke Island," he told media. "I think it's a fabulous place, I think it's tremendous.

"Having been there as well, I think I know far too many places in New Zealand and haven't visited most of them."

Ms Ardern suggested she take him to a Kiwi location he hadn't been to before.

"Rural Waikato it is!" she quipped, to which Mr Morrison suggested Te Awamutu.