TAIPEI, Taiwan (AP) — For the first time, China has publicized what it claims is an unwritten 2016 agreement with the Philippines over access to South China Sea islands.

The move threatens to further raise tensions in the disputed waterway, through which much of the world’s trade passes and which China claims virtually in its entirety.

A statement from the Chinese Embassy in Manila said the “temporary special arrangement” agreed to during a visit to Beijing by former president Rodrigo Duterte allowed small scale fishing around the islands but restricted access by military, coast guard and other official planes and ships to the 12 nautical mile (22 kilometer) limit of territorial waters.

The Philippines respected the agreement over the past seven years but has since reneged on it to “fulfill its own political agenda,” forcing China to take action, the statement said.