(Reuters) -U.S. Steel and Nippon Steel ( NISTF ) said on Monday they had filed two lawsuits after U.S. President Joe Biden blocked the $14.9 billion buyout of the American steelmaker by the Japanese company.

One lawsuit asked a court to set aside Biden's order and the review process by a U.S. government panel.

The second lawsuit is against Cleveland-Cliffs, its CEO Lourenco Goncalves, and USW union President David McCall "for their illegal and coordinated actions" aimed at preventing the deal, U.S. Steel and Nippon Steel ( NISTF ) said.

(Reporting by Aatreyee Dasgupta in Bengaluru; Editing by Sriraj Kalluvila and Arun Koyyur)