By Alexandra Alper and Katya Golubkova

WASHINGTON (Reuters) – Nippon Steel’s $15 billion bid for US Steel has been referred to US President Joe Biden, a White House spokesman said, giving the president 15 days to decide on a tie up. which he previously said he opposed.

The Committee on Foreign Investment in the United States (CFIUS), which reviews foreign investments in the US for national security risks, referred the bid to Biden after it failed to reach a consensus.

“We have received the CFIUS evaluation and the President will review it,” a White House spokesman said. President-elect Donald Trump, who is set to take office on January 20, also opposed the deal, which was first announced in December.

Nippon Steel said Tuesday it was notified of the CFIUS letter.

“We urge him (Biden) to reflect on the great lengths we have taken to address any national security concerns that have been raised and the significant commitments we have made to the development of US Steel, ” Nippon Steel said in a statement.

Nippon Steel and US Steel previously said they planned to close the deal before the end of 2024.

The Washington Post first reported the referral to Biden on Monday.

CFIUS said on Monday that allowing Nippon Steel to take over US Steel could result in a decline in domestic steel production that represents “a national security risk”, according to the Washington Post.

Nippon Steel says it can eliminate that risk by appointing US citizens to top management and board of director positions at US Steel, but the committee is divided on whether those remedies are sufficient, said the newspaper.

The US Treasury Department, which leads CFIUS, and the Commerce Department, declined to comment.

The deal, crucial for Nippon Steel’s global expansion, also faces opposition from the United Steelworkers, a powerful labor union that has been key for Democrats and Republicans in the swing state of Pennsylvania during Nov. 5 presidential elections.

The union worries that Nippon Steel could import US steel from its international mills, destroying a company that helped build the Empire State Building and the allied armed forces in World War II.

Nippon Steel has previously denied using the deal as a cover to import steel and has made a series of pledges to protect jobs and invest in US facilities it sees as key to its future growth.

“The US Steel deal is a once-in-a-lifetime opportunity for Nippon Steel to fuel its growth,” said SBI Securities analyst Ryunosuke Shibata.

The US is the only developed country where domestic steel demand is increasing, with the highest steel prices in the world due to production capacity falling short of domestic demand, he added.

With US Steel, Nippon Steel aims to increase its global steel production capacity to 85 million metric tons per year from 65 million tons today and the asset is the core of its goal to increase production capacity to more than 100 million tons in the long term.

Nippon Steel faces a $565 million penalty to US Steel if the deal collapses, which could also be a major blow to the Japanese steelmaker’s overseas expansion. It has previously said it may pursue legal action against the US government if the deal breaks down.

Since Japan is the largest foreign investor in the US, Japanese Prime Minister Shigeru Ishiba last month sent a letter to Biden asking him to approve Nippon Steel’s acquisition of US Steel.

“The transaction … advances US national and economic security by investing in manufacturing and innovation – in a company based in one of the United States’ closest allies – and establishes a steel alliance to will overcome the competitive threat from China,” US Steel said in a statement.