Despite making "significant progress" in the latest talks on the Trans-Pacific Partnership (TPP) free-trade agreement, trade ministers representing the 12 countries taking part have conceded that negotiations will be on-going early next year.

It had been hoped that the pact, which is being negotiated between a dozen Pacific and Asian nations and the US, would be wrapped up by the end of 2013.

But following the end of discussions in Singapore earlier this week, US Trade Representative Michael Froman said ministers are set to reconvene "sometime next month."

He added: "Over the course of this meeting, we identified potential landing zones for the majority of key outstanding issues in the text. We will continue to work with flexibility to finalise these text issues as well as market access issues."

Expectations are that the agreement should be completed in early 2014.

Outstanding issues are thought to include tariff reductions on sensitive items such as footwear, and the yarn-forward rule of origin in textiles and apparel.

Speaking at a press briefing after the talks, Ambassador Froman admitted there is still "work to be done" on some market access issues.  

Textiles are a major issue in the talks because the negotiating parties include Vietnam, a major apparel producer that mainly sources yarns and fabrics from China and other Asian nations.

Under the "yarn-forward" rule, all the materials that go into a garment must originate and be assembled in one of the trade agreement's partner countries if it is to enter the US tariff-free.

Without this rule, the US textile industry is concerned that China would be able to export apparel more cheaply by routing its textile products through Vietnam for cutting and sewing, exploiting its favoured-trade status.

However, US apparel importers and retailers argue the rule as it stands is too restrictive, hinders new trade and investment in the sector, and renders most existing trade ineligible for preferential tariff treatment.

Instead, they want to be able to have the freedom to source materials and component products from the best suppliers, regardless of whether textiles from the US or partner countries are used.

TPP talks have been ongoing since 2009, with negotiators currently involved in the discussions including the US, Australia, Brunei, Canada, Chile, Malaysia, Mexico, New Zealand, Peru, Singapore, Vietnam and Japan.