Trade officials from Japan and the United States resumed negotiations over outstanding issues on market access for agricultural products such as beef and pork under the Trans-Pacific Partnership.

Both governments will explore ways to strike a deal, possibly this fall, regarding Japan's exceptional tariffs on some farm products, so that plenary talks on the 12-country free trade initiative can move forward, a Japanese official said.

A key topic in the talks that started Monday between Hiroshi Oe, deputy chief TPP negotiator for Japan, and Wendy Cutler, acting deputy U.S. Trade Representative, will be whether the United States allows Japan to introduce safeguard measures for beef and pork.

Japan has told the United States it will keep tariffs on rice, wheat, beef and pork, dairy products and sugar under the TPP. The gap has been a thorny issue between the two largest economies in the proposed U.S.-led pact.

Japan has been considering lowering tariffs on beef and pork under a TPP deal and demanded the United States allow introduction of measures to protect domestic livestock farmers that would limit imports of such products if they surge.

Tokyo and Washington resumed the talks on farm market access after nearly one-third of U.S. House of Representatives members, in a letter to President Barack Obama last week, urged Japan to open its market further.

If completed, the TPP will cover some 40 percent of global economic output. The other countries involved are Australia, Brunei, Canada, Chile, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam.