The world's fourth-largest steelmaker's planned $14.9 billion deal has drawn criticism from Democratic and Republican lawmakers and the powerful United Steelworkers (USW) union, the main union at the third-largest U.S. steel company.

The deal would move Nippon Steel closer to its goal of 100 million metric tons of global crude steel capacity, while significantly expanding its production in the United States.

In a statement to Reuters, Nippon Steel said that Mori has met with the U.S. Congress members 'to discuss how this acquisition will be beneficial to all stakeholders, including American industry and workers.'

"We look forward to engaging in dialogue with and seeking the understanding of relevant stakeholders throughout the process," it said without further details.

Japanese media outlet Nikkei Asia, which first reported last week's visit, said on Tuesday that a Nippon Steel delegation has met with Sen. John Fetterman, a Democrat from Pennsylvania, who is opposed to the deal, among others.

The deal's announcement comes as former U.S. President Donald Trump, an advocate of strong U.S. domestic businesses, tries to win the primary Republican presidential race to seek re-election in the November U.S. presidential contest.

(Reporting by Yuka Obayashi; Writing by Katya Golubkova; Editing by Kim Coghill)