WASHINGTON (Reuters) – The Italian government should not support China’s “Belt and Road” infrastructure plan, a spokesman for the White House’s group of national security advisers said on Saturday, calling it a “vanity project.”

On Friday, Italian Prime Minister Giuseppe Conte said that he might sign an accord with Chinese President Xi Jinping later this month, despite reports that the United States was concerned at the prospect of a key ally joining the venture.

“Italy is a major global economy and great investment destination. No need for Italian government to lend legitimacy to China’s infrastructure vanity project,” said spokesman Garrett Marquis on Twitter.

Xi is due to travel to Italy from March 22-24 and Conte said Rome and Beijing were looking to agree a framework deal during the state visit.

The “Belt and Road” plan, championed by Xi, aims to link China by sea and land with southeast and central Asia, the Middle East, Europe and Africa, through an infrastructure network on the lines of the old Silk Road.