U.S. Steel and Japan's Nippon Steel said Trump had approved their merger after they signed a national security agreement with the U.S. government.

In another challenge to the line between government and private interests, the Trump administration has cleared Nippon Steel’s $14 billion acquisition of US Steel, only after inserting a novel “class G” preferred share that gives any sitting president permanent veto power over major corporate decisions.

President Donald Trump would have unique influence over the operations of U.S. Steel under the terms of the investment being made by Nippon Steel.

President Trump on Friday cleared the way for Japan-based Nippon Steel to acquire U.S. Steel, though key details about the structure of the deal — including a possible "golden share" held by the federal government — remain unclear.