President Donald Trump on Wednesday blocked a China-backed investment company from buying an American chip maker.

The deal had already received a negative determination from the Committee on Foreign Investment, a U.S. government panel that reviews multinational deals for security risks. Canyon Bridge Capitals Partners, the Chinese government-backed investment fund, and Lattice Semiconductor Corp had appealed to the president to overrule the committee.

The White House said that deal posed a risk to U.S. national security due to the “potential transfer of intellectual property to the foreign acquirer, the Chinese government’s role in supporting this transaction, the importance of semiconductor supply chain integrity to the United States Government and the use of Lattice products by the United States Government.”

The move signals that the administration will closely scrutinize Chinese investments in U.S. technology companies, according to a person familiar with the matter. The administration has also launched an investigation into Chinese theft of U.S. intellectual property.