Russian agriculture consultancy IKAR raised its forecast for Russia's 2020 wheat crop by 1.5 million tonnes to 79.5 million tonnes due to higher yields in the central and Volga regions.
CBOT August soybean futures settled down 5-1/4 cents at $8.91-1/2 per bushel while the most-active November contract ended down 2-1/4 cents at $8.85-1/4.
CBOT December soymeal ended down $1.70 at $295.80 per short ton while December soyoil rose 0.14 cent to 30.06 cents per pound.
Another 351,000 tonnes of soybeans were sold to buyers in unknown destinations, the USDA said. Traders and analysts said those soybeans also were likely headed to China.
China said on Thursday it will stick to the Phase 1 trade deal it reached with the United States earlier this year.
The deals follow a USDA announcement on Tuesday that China bought 1.762 million tonnes of corn, its biggest single-day US corn purchase, and 129,000 tonnes of soybeans.
Trump on Tuesday ordered an end to Hong Kong's special status under US law to punish China for what he called "oppressive actions" against the former British colony.