Japan has proposed to lift tariffs on all items aside from its five "sacred" farm products within 10 years, according to sources involved in the Trans-Pacific Partnership trade talks.

By suggesting a relatively short moratorium period, the government is apparently trying to take a conciliatory stance in talks on the U.S.-led free trade pact, which is based on the principle of eliminating all tariffs.

Other parties involved in the TPP negotiations have proposed much longer moratorium periods— up to 20 or 30 years — for abolishing tariffs on goods they view as sensitive.

But Tokyo is insistent on retaining tariffs on imported rice, wheat, beef and pork, dairy products and sugar because farmers are worried that Japanese agriculture, which is highly protected, would be heavily damaged by a flood of foreign products.

A government official who briefed the press in Tokyo said that while significant progress had been made in some areas at a meeting of chief negotiators that began Tuesday in Salt Lake City, the contentious issues had yet to be discussed.

Acting Deputy U.S. Trade Representative Wendy Cutler, who met with a member of the ruling Liberal Democratic Party on Thursday in Tokyo, repeated that Japan should scrap tariffs on all items and proposed a moratorium of about 20 years on some of the five sacred products.

But Koya Nishikawa, a House of Representatives lawmaker who heads the LDP's TPP committee, rejected the proposal, the sources added.

Cutler is representing the U.S. in the three-day bilateral talks ending Friday in Tokyo, in parallel with the TPP negotiations.

As for how to deal with tariffs, negotiation sources said earlier that U.S. Trade Representative Michael Froman had proposed that Japan retain tariffs only on rice, but the two sides have been unable to meet halfway on the issue.