U.S. livestock farmers repeated on Thursday their call for Japan to lift all tariffs on beef and pork under the Trans-Pacific Partnership, rejecting Tokyo's proposal to partially cut the duties.

"Unequivocally not," Nick Giordano, vice president of the National Pork Producers Council, told reporters when asked if the council could possibly accept Japan's proposal in the negotiations for the U.S.-led trade pact.

Giordano told a teleconference that tariffs on pork have gone to zero in "every single free trade agreement we have ever had" and voiced concern that accepting Japan's proposal could encourage America's FTA partners to change their tariff systems.

Bilateral gaps over tariffs on beef and pork are a main sticking point in Japan-U.S. talks for an early signing of the TPP, including the latest round of their talks that ended Wednesday in Washington.

Japan has proposed applying a tariff quota system under which set quantities of imported goods in the five most sensitive farm product categories would be either tariff-free or subject to low duties.

"I don't think any offer is going to be accepted . . . unless it's something that goes to zero," said Bob McCan, president of the National Cattlemen's Beef Association.