Foreign Minister Winston Peters on Tuesday confirmed he would be meeting with Chinese counterpart Wang Yi later this week in Beijing to discuss "regional trade and security issues, including North Korea".

It was "very likely" the first landing of a Chinese bomber in the China South Sea would also come up, Mr Peters told reporters, declining to go into details.

New Zealand's Prime Minister, Jacinda Ardern, last week flagged the government would be stepping up its talks with the world's second-largest economy.

Its trade minister, climate change minister, and Ms Ardern are all expected to make trips to Beijing throughout the year.

New Zealand in 2008 became the first developed nation to sign a free-trade deal with China and the countries share an extensive trade relationship, particularly for New Zealand's key dairy industry.

The previous government in September agreed to negotiating a mandate to upgrade the deal.

That would be on this week's agenda as well, Mr Peters said.

New Zealand's government in March announced it would be stepping up its involvement in the Pacific - including with more than $NZ700 million ($A645 million) in new aid - after a speech by Mr Peters warned of wealthier countries moving into the region.

But both he and Ms Ardern have avoided naming China's growing influence in the region as a concern or the cause behind the move.

Meanwhile, Australian Foreign Minister Julie Bishop said she had raised concerns about the South China Sea during her meeting with Mr Yi at the G20 foreign ministers meeting in Buenos Aires - but described the discussions as "very warm".

Last week, Chinese communist party mouthpiece the Global Times said Australia-China relations were among the worst of all Western nations.

No Australian minister had visited the Chinese mainland for eight months before Trade Minister Steve Ciobo broke the drought last week.

Prime Minister Malcolm Turnbull is expected to visit China this year.

Australian Associated Press