A Chinese and U.S. flag at a booth during the first China International Import Expo in Shanghai, November 6, 2018.

U.S. and Chinese deputy trade negotiators were set to resume face-to-face talks on Thursday for the first time in nearly two months as the world's two largest economies try to bridge deep policy differences and find a way out of a bitter and protracted trade war.

The negotiations on Thursday and Friday are aimed at laying the groundwork for high-level talks in early October that will determine whether the two countries are working towards a solution or are headed for new and higher tariffs on each other's goods.

A delegation of about 30 Chinese officials, led by Vice Finance Minister Liao Min, were set to launch talks on Thursday morning at the U.S. Trade Representative's (USTR) office near the White House. The U.S. side is expected to be led by Deputy USTR Jeffrey Gerrish.

The discussions are likely to focus heavily on agriculture, including U.S. demands that China substantially increase purchases of American soybeans and other farm commodities, a person with knowledge of the planned discussions told Reuters.

Two negotiating sessions over the two days will cover agricultural issues, while just one will be devoted to texts covering core changes to strengthen China's intellectual property protections and end the forced transfer of U.S. technology to Chinese firms.

"Sessions on agriculture will get a disproportionate amount of air time," the source said, adding that one of these sessions also will include a focus on U.S. President Donald Trump's demand that China cut off shipments of the synthetic opioid fentanyl to the United States.

Trump is eager to provide export opportunities for U.S. farmers, one of his key political constituencies who have been battered by China's retaliatory tariffs on U.S. soybeans and other agricultural commodities.