U.S. President Joe Biden said on Wednesday he thinks Twitter's top boss Elon Musk's relationships with other countries was worthy of being looked at.
Mr. Biden was asked at a news conference whether he thought Mr. Musk was a threat to national security and if his acquisition of Twitter with help from a Saudi Arabian conglomerate should be investigated by the U.S. government.
"I think that Elon Musk's cooperation and or technical relationships with other countries is worthy of being looked at," Mr. Biden said.
"Whether he is doing anything inappropriate, I'm not suggesting that. I'm suggesting they're worth being looked at."
The White House said last month that reports the United States was discussing launching a national security review of some of Mr. Musk's ventures including Twitter were "not true."
Mr. Musk's purchase of Twitter sparked concerns his companies, such as electric carmaker Tesla, could face pressure from countries trying to control online speech. The world's richest man, is CEO of Tesla and rocket company SpaceX, among others.
Tesla operates a factory in Shanghai, China, which accounted for about half of Tesla's global deliveries last year.
Mr. Musk previously suggested that tensions between China and Taiwan could be resolved by handing over some control of Taiwan to Beijing. Mr. Musk also said China has sought assurances that he would not offer SpaceX's Starlink internet service there.