Diplomats at a United Nations conference in Busan, South Korea, failed to reach agreement on the world’s first treaty to tackle plastic pollution on Sunday. They said they would reconvene in future months to try again.

Delegates from more than 170 countries attempting to negotiate a treaty to curb global plastic pollution ended a weeklong meeting in Busan early Monday without an agreement, pushing talks to another session next year.

About 200 nations couldn’t agree on a treaty to curb plastic pollution after two years of divisive negotiations, but said they made some progress and would reconvene the talks next year.