US President Donald Trump on Tuesday threatened further retaliation against China if Beijing targets U.S. agricultural or industrial workers amid a trade dispute, and accused China of trying to sway the U.S. election by targeting farmers, Reuters reported.

Trump made the accusations in a pair of Twitter posts as the two sides launched new trade tariffs in an escalating trade dispute.

Beijing said it would retaliate with tariffs against $60 billion worth of American products after Trump on Monday imposed 10 percent tariffs on about $200 billion worth of imports from China.

“China has openly stated that they are actively trying to impact and change our election by attacking our farmers, ranchers and industrial workers because of their loyalty to me,” Trump wrote. It was not clear what statement from Beijing the president was referring to in his post.

“There will be great and fast economic retaliation against China if our farmers, ranchers and/or industrial workers are targeted!” Trump added. Trump won the 2016 presidential contest with strong support from those farmers and blue-collar voters.