(AFP) - A global treaty to curb plastic pollution will be secured at a summit in South Korea next month, the chair of the talks pledged Wednesday, although he cautioned there were still complex disputes and the time frame was a "big challenge".

Ecuador's Luis Vayas Valdivieso said the clock was ticking if nations are to seal a potentially groundbreaking agreement at final UN-convened talks in South Korea late November, adding that divergences remain between countries.

Vayas Valdivieso said his mandate is "to achieve an effective treaty, an effective legally binding instrument" and "we're going to deliver on that mandate at the end of Busan".

However, "I am in the hands of the members," he told a lecture in Japan.

"We do have divergences still in our negotiation, still some complex issues that still need to mature a bit more."

Negotiators have met several times to discuss a deal that could include production caps, rules on recyclability, and bans on certain plastics or chemical components.

At previous talks, oil-producing nations such as Saudi Arabia objected to limiting plastic production, wanting to instead focus on recycling.

Meanwhile, dozens of countries in a "high-ambition" coalition, including the majority of the European Union, are calling for tougher measures.

Vayas Valdivieso said that with only seven days of negotiations in Busan, time will be a "big challenge".

But he expressed hope for a deal "with credible rules to end plastic pollution".

"We must succeed in Busan for the wellbeing of our planet, for the wellbeing of human health," he said.

Plastic production has doubled in 20 years and at current rates it could triple by 2060, according to the OECD.

Yet over 90 percent of plastic is not recycled, with much of it dumped in nature or buried in landfills.

In an attempt to whittle down the unwieldy draft document and speed up negotiations in Busan, Vayas Valdivieso has been producing so-called "non-papers" based on talks with countries.

The papers have no legal basis as negotiating documents but could serve as a starting point for the last round of talks if the parties agree to accept them.

Vayas Valdivieso said on Wednesday he hoped to publish a third non-paper in the coming days with "as much text as possible".

But Busan does not mark the end of efforts to tackle plastic pollution, he added, as any treaty should be "a living convention that will get stronger and stronger in the future."

© Agence France-Presse