The latest negotiations toward a global plastic treaty concluded late Sunday with disagreement about how the pact should work and frustration from environment groups over delays and lack of progress.

Negotiators spent a week at the UN Environment Program (UNEP) headquarters in Nairobi haggling over a draft treaty to tackle the growing problem of plastic pollution found everywhere, from ocean depths to mountaintops to human blood.

It is the third time negotiators have met since 175 nations pledged early last year to fast-track talks in the hope of finalizing a treaty by 2024.

The meeting in Nairobi was supposed to advance the process by fine-tuning the draft treaty and starting discussions about what concrete measures should target pollution from plastic, which is made from fossil fuels.

But the treaty specifics were never really addressed, with a small number of oil-producing nations — particularly Iran, Saudi Arabia and Russia — accused of employing stalling tactics seen at previous negotiation rounds to hinder progress.

“Unsurprisingly, certain countries are blocking progress on every term, playing obstruction and procedural maneuvers,” Carroll Muffett from the Center for International Environmental Law told Agence France-Presse (AFP).

Lacking leadership

In closed-door meetings, so many new proposals were put forward that the text — instead of being revised and streamlined — ballooned in size over the course of the week, observers following the talks said.

Graham Forbes from Greenpeace said the meeting had “failed” its objectives and urged governments to take a harder line in future negotiations on nations not acting in good faith.