WASHINGTON (Reuters) - U.S. Treasury Secretary Janet Yellen said on Wednesday that Nippon Steel's ( NISTF ) blocked acquisition of U.S. Steel received a "thorough analysis" by an interagency national security review body that was sent to President Joe Biden.

Yellen, in a live interview on CNBC, said she could not discuss specifics of the review of the merger blocked by Biden last week that is now the subject of a lawsuit that alleges that the review by the Committee on Foreign Investment in the United States (CFIUS) was not conducted in good faith and was prejudiced by Biden.

"I think, as you know, there is ongoing litigation over this case, and as head of CFIUS, I regret there is very little substantive that I can say to you about this," Yellen said. "Other than that, CFIUS did analyze the specifics, as it always does of this situation, and prepared a thorough analysis to go to the president."