The Trump administration supports bipartisan bills in Congress to toughen US foreign investment rules amid growing concern about Chinese efforts to buy US high-tech companies, the White House said in a statement on Wednesday.The legislation would broaden the government's power to stop foreign purchases of US firms by strengthening the Committee on Foreign Investment in the United States (CFIUS).The bills "would achieve the twin aims of protecting national security and preserving the longstanding United States open investment policy," the White House said.