Nippon Steel Corp. and United States Steel Corp. are on pace to finalize their $14.1 billion combination with President Donald Trump’s administration before a deal deadline later this month, capping an 18-month saga to combine the steelmakers into the world’s second-largest producer.

Talks on the agreement between the companies and the US government are ongoing and expected to reach a conclusion before a June 18 merger agreement deadline, according to people familiar with the matter, speaking on condition of anonymity given that talks are confidential. US Steel and Nippon Steel declined to comment. A Treasury Department spokesperson declined to comment.

The companies, their investors and advisers to the deal are still awaiting final terms marking the end of Nippon Steel’s takeover of the US steelmaker, but talks with the Committee on Foreign Investment in the United States are progressing and poised to be finalized before the deal deadline, said the people.

However, final details have not been fully ironed out and talks are ongoing, the people said. Failure to reach a deal could mean reopening the merger agreement at least partly and potentially spur new fronts of negotiation.

US Steel shares jumped as high as $54.24 after the Bloomberg report — the highest since Nippon Steel’s $55-a-share offer was announced in mid-December 2023 — before paring gains.

A court case stemming from President Joe Biden’s block of the transaction is ongoing, and included a June 5 deadline for an update. In a court filing Thursday, the US government sought an extension of eight days, until June 13.

The companies and government continue “to work to reach a resolution that would obviate the need” for the case, the filing said. The extension is warranted given the “ongoing efforts to reach a resolution,” according to the filing, submitted by Justice Department lawyers.

A final deal would clear the way for the Japan-based steelmaker to finally own the once-iconic American producer — albeit with some measures of American control, such as over board seats. Trump’s self-proclaimed “big deal” that extracted further concessions from Nippon Steel would also add decades of life to existing US Steel mills that have long beleaguered the company’s bottom line due to their urgent need for significant, and unavailable, capital investments.

The agreement includes a requirement that US Steel, as a subsidiary, will retain its headquarters in Pittsburgh. The deal also includes provisions for a US management team, a majority of US nationals on the board and US government approval of “key” board positions, Senator David McCormick, a Pennsylvania Republican, told Fox News Sunday earlier this week. It’s also poised to require an American chief executive officer, some of the people said.

Trump said Friday that US Steel workers would receive a $5,000 bonus and that $2.2 billion of a $14 billion proposed investment would be earmarked to increase steel production at the Mon Valley Works facility. Another $7 billion would be spent to modernize steel mills, expand ore mining and build facilities across Indiana, Minnesota, Alabama and Arkansas. And, he added, US Steel wouldn’t announce layoffs or outsourcing, and its blast furnaces must remain at “full capacity” for at least 10 years.

While some investors have worried about Cfius finalizing terms by a certain date, people familiar with the matter said the security panel’s decision wasn’t bound to a due date given its investigation wasn’t done through a typical process.

US Steel’s recent stock performance suggests investors are optimistic the deal will succeed. Shares of the American steelmaker have been trading above $53 a share since May 27 — close to Nippon Steel’s all-cash offer.