US President Joe Biden reportedly has "serious concern" about Nippon Steel's takeover of US Steel, and plans to issue a statement to that effect.

Japan's largest steelmaker announced in December that it had inked an agreement to acquire US Steel for about 14 billion dollars.

A report in British newspaper the Financial Times quotes sources as saying Biden will express serious concern about the deal. The president will communicate his feelings on the matter in a statement before the arrival of Prime Minister Kishida Fumio for a state visit on April 10.

The newspaper says the White House has privately informed the Japanese government of the president's plans.

US Steel has its headquarters in Pennsylvania, a key swing state. The United Steelworkers union is an outspoken opponent of the takeover. The organization is a major supporter of the Democratic Party.

Biden appears eager to lock in the union's support before the presidential election in autumn.

Japan's Chief Cabinet Secretary Hayashi Yoshimasa has declined to comment. He said he won't be drawn on matters related to the management of individual companies.

Hayashi said, "The Japan-US alliance has never been stronger. The two countries will continue to work together to achieve sustainable and inclusive economic growth in the Indo-Pacific region. We will also continue to cooperate on maintaining and strengthening a free and open economic order based on rules, and in the field of economic security."