Negotiations on a multilateral free trade agreement between Japan and the United States remained stalled on Thursday.

Economy Minister Akira Amari held a day of intense talks with US Trade Representative Michael Froman. Amari told reporters that progress was “difficult.”

The talks focus on reducing Japan’s tariffs on several key items, including rice, meat and dairy products.

The United States has indicated it would let Japan keep higher duties on rice and wheat, provided its own quota of duty-free rice exports to Japan is expanded.

The US is also seeking the near-complete elimination of tariffs on pork and beef.

Officials in Tokyo have been resisting these demands to protect domestic producers.