The soybeans will be shipped to China during the current marketing year, which ends on Aug. 31.
The US government also announced that private exporters reported the sale of 274,000 tonnes of soybeans for shipment to unknown destinations, which traders typically assume to be China.
USDA said on Monday that China bought 612,000 tonnes of soybeans.
China, which bought about 60 percent of the 2017, US soybean crop, cut off purchases of US supplies amid trade tensions between the two countries.
Beijing slapped 25 percent tariffs on US soybeans and other goods, retaliating against similar tariffs imposed by Washington.
Those tariffs remain and sales to China have gone to state-run companies rather than private importers.
The tariffs, which brought a halt to US soybean sales to China, caused American stocks of the oilseed to balloon following a massive harvest, lowering prices and threatening farmers' profits.
The trade war was enough to bring 2018, Chinese soybean imports from the United States down to their lowest level in a decade, with shipments down by half at 16.6 million tonnes.
Chicago Board of Trade soybean futures hit their highest since June on Friday after traders said Chinese state-run companies had booked at least 1 million tonnes of US soybeans.
At 8:38 a.m. CST (1438 GMT), the benchmark CBOT March soybean futures contract was down 2-1/2 cents at $9.16 a bushel.
The White House has committed to a March 2 tariff increase on $200 billion of Chinese goods if no deal is reached by March 1.