WASHINGTON—President Trump rolled out a $16 billion plan to help farmers hit by the trade conflict with China and suggested on Thursday that Huawei Technologies Co. could potentially be a bargaining chip in settling the dispute.

The developments came as financial markets fell again amid uncertainty over the fate of the trade talks, with the Dow Jones Industrial Average dropping 286.14 points, or 1.1%.

At a White House event with farmers, Mr. Trump said a deal with China was a “good possibility” but declined to give details. He said the U.S. campaign against Huawei could be up for negotiation, while also calling the telecom giant a “very dangerous” threat to national security.

“It’s possible that Huawei would be included in some kind of a trade deal,” he said.

The $16 billion farm plan, which won’t require congressional approval, largely consists of direct payments to U.S. farmers hit hard by Chinese tariffs on crops. The payments echo a similar program last year that was funded at $12 billion.