Nippon Steel is dropping a lawsuit against the United States government, chairman and CEO Eiji Hashimoto said as the company finalized its acquisition of United States Steel after an 18-month battle to complete the transaction.

The suit has been rendered moot as a result of the successful purchase of the American steel-maker, Hashimoto said in reply to a question from The Japan Times after his meeting with trade minister Yoji Muto on Thursday evening.

“We were able to achieve our objective, so there is no longer a meaningful reason to continue that case — in a good sense,” he explained.

A separate civil suit against a competitor and a union leader has not yet been dropped.

Nippon Steel and U.S. Steel filed the lawsuit against the U.S. government in January to challenge former U.S. President Joe Biden’s blocking of the transaction on national security grounds. They argued that the companies were denied due process and other rights, and claimed that the $14.9 billion transaction was blocked for political reasons.

U.S. President Donald Trump, who had voiced opposition to the deal during his presidential campaign, reversed his predecessor’s decision last week. He said the Japanese firm could buy the U.S. company if it signed a national security agreement with the U.S. government.

Nippon Steel finalized the transaction on Wednesday.

The civil suit alleges that United Steelworkers union President David McCall, Cleveland-Cliffs and Lourenco Goncalves, CEO of Cleveland-Cliffs, engaged in “illegal and coordinated actions” to sabotage the U.S. Steel acquisition.

Goncalves has dismissed Nippon Steel’s claims, saying the accusations are “baseless.”

An outspoken critic of the Nippon Steel-U.S. Steel deal, Goncalves described Japan as “evil” for “teaching China how to dump steel.” In the lawsuit, he was accused of launching a “public smear campaign” and “trafficking in xenophobic stereotypes” about foreign investors to kill the deal.

Cleveland-Cliffs made an in July 2023 to purchase U.S. Steel for $35 a share — later raised to $54, according to reports — in cash and stock. Nippon Steel made an all-cash a share.

McCall, who has been vocal in his opposition to the Nippon Steel transaction from the outset, said in a Wednesday statement that the union will “continue watching” and hold Nippon Steel to its commitments.

“We will decide how to proceed after closely observing how the other parties respond, so no final decision has been made on that yet,” Hashimoto said of the civil lawsuit.