Australia joined the U.S. in rejecting China’s expansive maritime claims in the South China Sea, calling them "inconsistent” with the 1982 United Nations Convention on the Law of the Sea.

"There is no legal basis for China to draw straight baselines connecting the outermost points of maritime features or ‘island groups’ in the South China Sea,” Australia’s mission to the U.N. wrote in a filing on Friday. "Australia rejects China’s claim to ‘historic rights’ or ‘maritime rights and interests’ as established in the ‘long course of historical practice’ in the South China Sea.”

The move aligns Australia with the Trump administration, which earlier this month reversed a previous policy of not taking sides in such disputes. In their move, both the U.S. and Australia cited a 2016 ruling by a U.N. tribunal that found China’s claims to waters also contested by the Philippines were unlawful.

The push by the two allies is meant as a response to what they see as an intensifying Chinese campaign to dominate the resource-rich South China Sea. China has engaged in a yearslong campaign to build bases and other outposts on shoals, reefs and rock outcroppings as a way of deepening its claims.

China’s mission to the U.N. didn’t immediately reply to a request for comment but it said earlier this month that the U.S. position "neglected the history and facts” around issues concerning the South China Sea.

Australia’s filing comes ahead of a planned meeting in Washington next week between the U.S. and Australian defense and foreign ministers.