Japan cabinet secretary says Solomon Islands-China pact may have impact on region

China's security agreement with the Solomon Islands may affect security for the region and is a probable topic for discussions between the leaders of Japan and New Zealand on Thursday, Japan's chief cabinet secretary said.

The security pact is a major inroad for China in the resource-rich Pacific, which Australia and New Zealand have for decades seen as their "backyard," and the White House said in a statement this week that the United States, Japan, Australia and New Zealand were concerned.

"This agreement is likely to have an impact on the overall region's security, so we are watching it with concern," Hirokazu Matsuno told a news conference.

Though he said many details of the deal remained unknown, it was likely to be a topic of discussion when Japanese Prime Minister Fumio Kishida and New Zealand Prime Minister Jacinda Ardern meet on Thursday.

"It's expected that there will be vigorous discussion of a free and open Indo-Pacific in the talks between the two leaders," he added.

Ardern, who is leading a trade delegation, arrived in Japan on Wednesday night and is set to leave on Saturday.