The coronavirus outbreak could reduce Chinese purchases of US agricultural products this year under the Phase 1 trade deal signed by the countries, White House national security adviser Robert O’Brien said on Tuesday.

The fast-spreading virus has killed more than 1 000 people in China, where there have been nearly 43 000 cases.

There have been another 319 confirmed cases in 24 other countries,including 13 in the United States.

“We expect the Phase 1 deal will allow China to import more food and open those markets to American farmers, but certainly as we watch this coronavirus outbreak unfold in China it could have an impact on how big, at least in this current year, the purchases are,” O’Brien told an event at the Atlantic Council.

The Phase 1 trade agreement, which was signed on January 15, calls on China to boost its purchases of US agricultural commodities by $40 billion over the next two years.

O’Brien said China plays a critical role in the global supply chain and the coronavirus could be disruptive.

“We’ll have to wait and see how it plays out and whether alternate suppliers can be found,” O’Brien said. “There’s no doubt that the virus could have an impact on the US economy and also on the world economy,” he said.