RALEIGH, North Carolina Sept 5 (Reuters) - U.S. Treasury

Secretary Janet Yellen on Thursday that the U.S. welcomes

foreign direct investment and rigorously reviews deals for

national security concerns, but declined to comment on reports

that President Joe Biden's administration is poised to block the

U.S. Steel-Nippon Steel ( NISTF ) merger.

Speaking to reporters in North Carolina, Yellen said the

ultimate decision on national security decisions on foreign

acquisitions rests with Biden.

On Wednesday, Reuters and other news outlets reported

that the Biden administration was poised to block Nippon Steel's ( NISTF )

$14.9 billion acquisition of U.S. Steel on national security

grounds.

Reuters reported that the administration told Nippon

Steel ( NISTF ) in a letter on Saturday that the merger would

pose a national security risk by harming the American steel

industry, citing three people familiar with the notice.

The deal faces opposition from numerous Democrats and

Republicans, with Vice President and Democratic presidential

candidate Kamala Harris saying on Monday she wants U.S. Steel to

remain "American owned and operated." Her Republican rival

Donald Trump has pledged to block the deal if elected.

Asked about the matter, Yellen said: "The United States

has the environment in which we very much welcome foreign direct

investment. We're seeing a huge amount of it in firms in North

Carolina that have been here for a long time and coming in

response to the Inflation Reduction Act."

She also said the U.S. has a "rigorous" review process

for national security implications of deals.

"That's a process that is intended to advise the

president, who makes the ultimate decisions on this," she said.