Spearheaded by the United States, the Western military alliance has looked to step up cooperation with Asia-Pacific democracies as it increasingly casts a wary eye at Beijing's growing might.

For the second year running, the leaders of Australia, Japan, New Zealand and South Korea attended a NATO summit.

NATO had planned to open a liaison office in Tokyo to help improve cooperation with Japan.

But France has blocked the move insisting that NATO should focus on its responsibility of protecting the Euro-Atlantic area.

"Whatever people say, geography is stubborn," Macron said after the NATO summit in Vilnius.

"The Indo-Pacific is not the North Atlantic, so we must not give the impression that NATO is somehow building legitimacy and a geographically established presence in other areas."

Macron's rejection of the NATO office has left diplomats of ally countries fuming.

NATO Secretary General Jens Stoltenberg insisted after meeting Japan's prime minister that opening the liaison office remains "on the table".

He said the alliance was looking to deepen cooperation with Tokyo in areas such as cyber and maritime security.

Stoltenberg said NATO's meeting with the Asian-Pacific partners sent the message that "security is not regional security it's global, and therefore we really have to stand together".

"China's heavy investments in new military capabilities demonstrates that," he said.

"We expect that China by 2035 will have 1,500 nuclear warheads on missiles that can reach North America and a whole of Europe, NATO territory."

The alliance chief said, "This is not about NATO becoming a global military alliance, but this is about recognising that this region faces global challenges and the rise of China is part of that."

The United States has long been pushing its European allies in NATO to take a tougher line on China, which Washington sees as its leading global rival.

In a statement on Tuesday, NATO leaders expressed worries about "the deepening strategic partnership" between Russia and China.

They urged Beijing to use its influence to get Moscow to halt its war on Ukraine.