WASHINGTON (Reuters) - The head of the U.S. Senate Banking Committee on Tuesday urged the White House to scrutinize the relationship between Nippon Steel ( NISTF ) and the Chinese steel industry, citing national security concerns amid bipartisan opposition in Congress to the Japanese company's $14.9 billion deal to acquire U.S. Steel Corp.

"As you examine this deal, I urge you to thoroughly investigate the allegations raised in this report and examine Nippon's ties to the Chinese government and the danger this merger poses to American national and economic security," Sherrod Brown, a Democrat from Ohio who chairs the Senate panel, said in a letter to Biden.

Nippon Steel ( NISTF ) and the White House did not immediately comment.

Brown, who is running for another term in the Nov. 5 elections, said that Nippon Steel ( NISTF ) in 1978 reached a deal to build China's "first fully modern steel complex," and he cited a report that Nippon operates nine facilities in China.

"Nippon's connection to the Chinese steel ecosystem and industrial policy agenda has concerning implications regarding ties to China's military-civil fusion strategy and quest for global economic power," Brown said in the letter.

The White House sees steel as critical to national security, and Biden said last month that U.S. Steel should remain domestically owned. His opponent in the Nov. 5 presidential election, former President Donald Trump, has promised to block the deal if he wins.

The deal is opposed by numerous lawmakers in the Midwest, including Brown, as well as by the United Steelworkers union.

Nippon Steel ( NISTF ) says it can help U.S. Steel grow.

"What U.S. politicians are concerned about is jobs and whether U.S. Steel can develop as an iconic U.S. company in the U.S.," Nippon Steel ( NISTF ) President Tadashi Imai told reporters last week.