Intensive talks between Japan and the United States aimed at breaking the deadlock over a huge pan-Pacific trade deal ended Thursday without agreement, as hopes faded of progress before Barack Obama arrives in Tokyo this month.
US Trade Representative Michael Froman and his Japanese counterpart Akira Amari said 18 hours of discussions had done little to reduce the "distance" between them, especially on farm and auto products.
"We made some progress over the last two days but still considerable differences in positions and key issues" remain, Froman told reporters.
"We agreed today that our negotiators will continue until the end of the week (with) the discussion on agriculture and autos," he said.
Amari separately told reporters the two sides, already major trade partners, had made "some progress" but added: "We still don't see where we will find common ground on each sector."
The Trans-Pacific Partnership (TPP) is an ambitious plan for a free trade agreement among 12 countries which, if realised, could cover 40 percent of global GDP.
It is a key plank in President Obama's foreign policy, and an effort to anchor the US firmly to a region that is increasingly feeling the pull of Beijing's mighty economy.
But huge sticking points remain, with the US and Japan -- the world's first and third largest economies -- fighting to protect important domestic industries.
Washington and many of the other parties to the talks -- which also involve Chile, Mexico, Canada and several Asian countries -- say Japan's unwillingness to open its lucrative agricultural market is a deal-breaker.
Putative suitors have long complained that sky-high tariffs -- on rice they are nearly 800 percent -- and non-tariff barriers, like overly-strict safety requirements, are naked protectionism.
Negotiators missed the end-of-2013 deadline they had set themselves -- a target that always looked ambitious but became much more so when Japan got involved in the talks during the year, and no new end-date has been set.
Tokyo was hoping that a free trade agreement agreed with Canberra this week, which will see tariffs on Australian beef slashed, would help bounce Washington into compromises, but US diplomats appear to have stood firm.
Japanese Prime Minister Shinzo Abe instructed Amari to accelerate the negotiations ahead of Obama's arrival in Japan on April 23 or 24 for a state visit that had at one point been expected to crown the TPP.
But Amari acknowledged Thursday that substantial progress looks unlikely ahead of that.
"The Japan-US summit scheduled later this month is one occasion, but it's not necessarily the deadline to settle the talks."