United States President Donald Trump has ordered the Commerce Department to launch an investigation into the national security harm posed by lumber imports, laying the groundwork for new tariffs.

The White House said that Trump signed a memorandum on Saturday to that effect, ordering Commerce Secretary Howard Lutnick to start a security investigation under Section 232 of the Trade Expansion Act of 1962.

The act allows the president to restrict imports through tariffs or other appropriate measures if an import poses a threat to national security.

The investigation reportedly not only covers lumber imports but also derivative products, such as imports of South Korea's kitchen cabinets made of U.S. lumber that had been exported.

A White House official reportedly said that allies such as Canada, Germany and Brazil are dumping lumber into the U.S. market at the expense of U.S. economic prosperity and national security.

The official, however, added that the probe will also focus on derivative products such as kitchen cabinets, saying that the logs exported from the United States are coming back from China and South Korea.