CHICAGO — U.S. agricultural machinery maker Deere & Co said on Wednesday it would monitor Beijing’s new tariff proposals to evaluate their impact on the company and its customers.

The statement came after shares of U.S. exporters of everything from planes to tractors fell after China retaliated against the Trump administration’s tariff plans by proposing duties on key U.S. imports including soybeans, planes, cars, beef and chemicals.

The tit-for-tat retaliatory policies are feared to hit U.S. farm exports, exacerbating the troubles of farm equipment makers, which have been battling weak domestic demand for the past 4 years.

Deere shares fell as much as 6.2% on Wednesday and were still down 3.8% at $147.24 in afternoon trading.

“We strongly encourage officials to work toward a timely resolution to limit uncertainty for farmers and avoid any meaningful disruption to agricultural trade,” said Ken Golden, director of global public relations at Deere.