Nippon Steel plans to invest $14 billion in U.S. Steel's operations including up to $4 billion in a new steel mill if the Trump administration green lights its bid for the iconic U.S. company, according to a document and three people familiar with the matter.

The efforts to push through Nippon Steel ’s proposed takeover come as Japanese negotiators are seeking to lower a 24 per cent tariff on the country’s imports into the US introduced by the Trump administration. Japanese officials signalled their intent last week to hold out for a better agreement.

Nippon Steel Corp. has bolstered its pledge to invest in United States Steel Corp. in the event that President Donald Trump approves the Japanese company’s proposed $14.1 billion takeover, according to a person familiar with the matter.