Eleven countries negotiating a proposed free trade agreement in the Asia-Pacific appear to be on the verge of formally inviting Japan into the talks, diplomatic and industry sources said on Thursday.

Top trade officials from the 11 countries participating in the Trans-Pacific Partnership (TPP) talks are meeting on Friday in Surabaya, Indonesia, ahead of the annual Asia-Pacific Economic Cooperation (APEC)) trade ministers meeting this weekend.

Japan, the world’s third-largest economy, struck a deal with the United States last week to get Washington’s support to join the TPP talks. But all 11 TPP countries have to agree to let Japan into the negotiations, which are already nearly three years old.Flag of Japan wavy business strategy

A diplomatic source, speaking on condition she not be identified because she was not authorized to discuss the matter publicly, said there was “momentum” behind Japan’s bid to join the talks, although some countries like New Zealand are still seeking assurances Japan is willing to discuss phasing out tariffs in all sectors, including sensitive ones like dairy.

Mexico and Canada are said to also have questions about the implications of the U.S.-Japan deal struck last week, which calls for Washington and Tokyo to negotiate separately on autos and some other issues and then incorporate the results into the overall TPP pact.

The TPP talks are officially slated to conclude this year, although many trade experts expect them to stretch into 2014. Some countries on Thursday were still looking for assurance that Japan’s entry would not slow the talks down, diplomatic sources said.

A U.S. industry official, also speaking on condition she not be identified because she was not authorized to discuss the matter publicly, said she expected the TPP countries to issue a statement on Friday welcoming Japan into the negotiations.

But the document could be carefully worded to reflect unresolved concerns that some countries still have, she said.

Japan is pressing for a decision on its entry because it wants to participate in the July round of negotiations, which would require the White House to quickly give Congress 90-day notice of its intention to begin trade talks with Tokyo.

The 11 countries currently in the TPP talks are the United States, Mexico, Canada, Australia, New Zealand, Chile, Peru, Singapore, Vietnam, Malaysia and Brunei.

A 17th round of talks is currently scheduled for May in Peru. The dates and location of the 18th round in July have not yet been announced.

(Reporting by Doug Palmer; Editing by Phil Berlowitz)