The White House is weighing some curbs on U.S. investments in China, a source familiar with the matter told CNBC. This discussion includes possibly blocking all U.S. financial investments in Chinese companies, the source said.It’s in the preliminary stages and nothing has been decided, the source said. There’s also no time frame for their implementation, the source added.Restricting financial investments in Chinese entities would be meant to protect U.S. investors from excessive risk due to lack of regulatory supervision, the source said.The deliberations come as the U.S. looks for additional levers of influence in trade talks, which resume on Oct. 10 in Washington. Both countries slapped tariffs on billions of dollars worth of each other’s goods. The discussions also come as the Chinese government is taking steps to increase foreign access to its markets.Bloomberg News first reported earlier on Friday that Trump administration officials are considering ways to limit U.S. investors’ portfolio flows into China, including delisting Chinese companies from American stock exchanges and preventing U.S. government pension funds from investing in the Chinese market.Shares of Alibaba, Baidu and other Chinese companies plunged following the news. China’s yuan weakened to 7.15 against the dollar on the report.The White House declined to comment.