French President Emmanuel Macron on Wednesday opposed a NATO push to open a liaison office in Japan, a rebuff that has revealed cracks within the Western military alliance.

Spearheaded by the United States, the alliance has looked to step up military cooperation with its Asia-Pacific partners.

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, but France 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 Lithuanian capital 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."

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

Beijing has warned against what would be a further expansion of NATO presence in the Asia-Pacific region, calling it a move that could disrupt regional peace and stability.

(With input from AFP)