TOKYO — Japanese farmers voiced concern Thursday that the United States may step up pressure on Japan to further open up its agricultural market after the countries’ leaders agreed to start trade negotiations on a bilateral basis.

“I hope the transparency of the negotiation process will be thoroughly ensured so that local farmers won’t face even more worries,” said Toru Nakaya, president of the Central Union of Agricultural Co-operatives.

At their summit Wednesday in New York, Japanese Prime Minister Shinzo Abe and U.S. President Donald Trump agreed to start bilateral trade talks while they “respect positions of the other government.”

According to the joint statement issued following the summit, Tokyo’s stance is that it will not make bigger concessions than terms already agreed to under existing free trade agreements such as the Trans-Pacific Partnership, a multilateral framework from which the United States has withdrawn.

U.S. Trade Representative Robert Lighthizer has singled out beef exports to Japan as an area of concern.

An official at an agricultural cooperative in Hokkaido said, “The bottom line is the standard set by the TPP. I hope (the two countries) will make sure they abide by the content of the joint statement.”

Washington’s push for bilateral trade talks comes as its farmers have said the country is lagging behind other major farming nations, such as Australia, in exporting beef to Japan.

Even before TPP members reached their accord, Japan began lowering its tariffs on Australian beef from 38.5 percent in stages, since a Japan-Australia free trade agreement took effect in 2015.

Once the TPP takes effect, Japan’s 38.5 percent tariff on fresh and frozen beef from other member states will be incrementally cut to 9 percent over 16 years.