WASHINGTON, Oct 29 (Reuters) - The U.S. Department of Agriculture is not planning to extend an up to $12 billion aid package for farmers into 2019, Secretary Sonny Perdue said on Monday, to mitigate farmer losses due to the imposition of tariffs on American exports.

"Farmers are very resilient and adept in making their planning and marketing decisions based on the current market," Perdue told reporters on the sidelines of an event in Washington.

The Trump administration in July authorized the aid to shield farmers and ranchers from the repercussions of trade disputes between the United States and China, the European Union and others.

The United States has slapped tariffs on $250 billion worth of Chinese goods this year as part of Republican President Donald Trump's vow to cut the U.S. trade deficit with China.

Beijing retaliated by hitting $110 billion of U.S. products, including the agriculture sector, prompting the USDA to offer compensation to farmers of soybeans, sorghum, corn, wheat, cotton, dairy and hogs.

China, traditionally the biggest buyer of U.S. agriculture exports, has been largely out of the market for several products, leaving farmers struggling with a supply overhang.

"These facts are known now ... So farmers, even under financial duress, will make their best business decision for 2019 without the expectation of a marker facilitation program," Perdue said.

The USDA outlined the allocations of farm aid for the first tranche of $6 billion at the end of August. Perdue said he did not expect the second tranche to be outlined any later than December, adding that the amount was still being discussed.

"We are continuing to looking at market conditions. We are discussing this really as we speak. Frankly right now, we see no change in the amount," he said. (Reporting by Humeyra Pamuk Editing by Tom Brown)