The US Department of Agriculture has to date paid out $8.52 billion in direct payments to American farmers as part of the 2018 aid program, designed to offset losses from trade tariffs by China and other trading partners, a spokesman for the agency said.

US President Donald Trump last year pledged up to $12 billion in aid to farmers, a key constituency, to help offset losses due to Chinese tariffs imposed in response to Washington's levies on Chinese goods.

A USDA spokesperson said the department had as of Wednesday paid out a total of $8.52 billion in direct payments, one portion of a wider trade mitigation program which also includes support up to $1.2 billion through commodity purchases and $200 million allocated to developing foreign markets.

The top five commodities that received aid were soybeans, corn, wheat, cotton and sorghum while the top five states receiving the payments were Illinois, Iowa, Kansas, Nebraska and Indiana, the USDA spokesman said.

Farmers have complained about the slow pace of the rollout of aid payments, which were hit by a month-long partial government shutdown that ended earlier this year. Floods in the Midwest coupled with a lingering trade dispute with China and tumbling commodity prices have hit them hard.

China has zeroed in on US farmers with tariffs after Trump imposed duties on $250 billion worth of Chinese goods last year as part of his vow to cut the US trade deficit with China. Beijing slapped a 25 percent tariff on US soybeans in retaliation. That effectively shut down US soybean exports to China, worth around $12 billion last year.

With no quick end to the trade war in sight, particularly after the latest round of talks between Beijing and Washington last week ended with no progress, the Trump administration is now working on a second aid program to support farmers.