A Chinese agricultural delegation canceled a planned visits to farms in Montana and Nebraska that had been scheduled for the coming days, officials said Friday.

But a spokesman for the US Trade Representative's Office told AFP the mid-level trade talks with Chinese officials underway in Washington were continuing as planned into Friday afternoon.

Word of the canceled visits, which were set to occur ahead of high-level trade negotiations expected next month, sent stocks tumbling.

The news some Chinese officials left earlier than expected knocked more than 100 points off the Dow Jones Industrial Average, amid concerns broader trade talks had again hit a roadblock.

Stocks closed in the red as investors are apprehensive about efforts to resolve the protracted trade war between Washington and Beijing, which is weighing on the global economy and feeding recession fears.

Rebecca Colnar, a spokesperson for the Montana Farm Bureau, told AFP a Chinese embassy official informed her Friday that the hastily-planned tour would not go forward due to an "updated agenda."

"He said they need to return to China," Colnar said, adding that the Montana Farm Bureau had only learned of a possible visit on Wednesday.

"It's not something we had planned for weeks. It was all very quick."

China's Vice Agriculture Minister Han Jun was part of the delegation that had been expected to travel to Montana.

Christen Kamm, spokeswoman for the Nebraska Department of Agriculture, said a visit to her state also had been canceled.

"We were informed this morning that the Chinese delegation will no longer visit Nebraska," she told AFP.

The Chinese embassy did not immediately respond to a query from AFP.

Since the start of the dispute last year, Chinese officials have largely boycotted US farm exports, severely damaging revenues in the American agricultural sector, particularly soy beans and pork.

Ministerial level talks are due to be held in Washington next month, but the date has not yet been announced.

US President Donald Trump told reporters on Friday that China had again resumed purchases of US farm exports but said he was seeking a grand bargain to address Washington's trade grievances with Beijing.

"China has been starting to buy are our agricultural product over the past week. Very big purchases," he said. "But that's not what I'm looking for. We are looking for the big deal."