Farm minister Yoshimasa Hayashi told U.S. Ambassador John Roos on Tuesday that Japan is opposed to participation in the Trans-Pacific Partnership free-trade negotiations if abolishing tariffs without exceptions is a precondition.

Noting that the Liberal Democratic Party pledged ahead of the election in December that it is against joining the talks if such a condition exists, Hayashi said, "We will work on the issue based on that view," according to an official in the agriculture ministry.

The official declined to speak in detail about how Roos responded but said he thought the ambassador "comprehended" Hayashi's remarks.

Roos also met with trade minister Toshimitsu Motegi, during which Motegi said Japan wants to pursue free-trade agreements, according to an official in the Ministry of Economy, Trade and Industry.

Motegi said Saturday on TV that the government will come up with a "unified estimate" on how the TPP could affect the Japanese economy.

It was reported last August that the farm ministry came up with an estimate that Japan's annual agriculture, forestry and fisheries output could fall by ¥3.4 trillion if tariffs are scrapped, but TPP proponents have questioned the validity of the calculation.

A new estimate is likely to be announced before the Upper House election this summer.

Under the previous administration led by the Democratic Party of Japan, Tokyo held consultations with the TPP negotiating members, including the United States, toward participating in the talks. But concerns remain, especially in the farming sector, which fears an influx of cheap produce from overseas under lowered tariffs.