WASHINGTON (REUTERS) - US President Donald Trump's national security adviser, Mr Robert O'Brien, acknowledged that the coronavirus outbreak could impact the phase one trade deal between the United States and China, a CNN reporter said on Twitter on Tuesday (Feb 11).

"This could have an impact on the phase one deal," Mr O'Brien told an audience at the Atlantic Council in remarks on the outbreak, according to the CNN reporter.

He also said the virus outbreak in China could reduce Chinese purchases of American agricultural products this year.

"We expect the phase one 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," Mr O'Brien said.

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.

The phase one trade agreement, which was signed on Jan 15, calls on China to boost its purchases of US agricultural commodities by US$40 billion (S$55.5 billion) over the next two years.

Mr 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," Mr 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.