Jan 2 (Reuters) - The United Steelworkers union

expressed concerns about Nippon Steel's ( NISTF ) latest proposal

that gives the U.S. government veto power over any potential

reductions in U.S. Steel's production capacity, if they get the

approval to merge.

The union, which has opposed U.S. Steel's merger with the

Japanese steel giant, said Nippon's offer fails to commit to

sustaining production over the long term or enhancing domestic

capacity in integrated facilities.

"Protecting capacity only means moth-balling our equipment,

allowing it to rust away to the point that it is no longer

feasible to re-start," the union said in a statement on its

website on Thursday.

The proposal "is nothing but a "Hail Mary" pass destined to

fall to the ground," it added.

On Tuesday, reports said Nippon Steel ( NISTF ) made a proposal to

give the government a final say over any potential production

cuts, as part of its efforts to secure President Joe Biden's

approval for acquiring the American steelmaker.

In 2023, Nippon clinched the deal to buy U.S. Steel at a

hefty premium, but the merger has since faced opposition from

the powerful Steelworkers' union as well as politicians.

"The truth remains that this transaction is the best way to

ensure that U.S. Steel, including its employees, communities,

and customers, will thrive well into the future," U.S. Steel

said on Thursday in response to the union's statement.

The Committee on Foreign Investment in the United States

(CFIUS) has referred the decision to approve or block the deal

to Biden, who must decide on the deal by Jan. 7.

If he takes no action, it would result in the merger's

automatic approval.

Nippon Steel ( NISTF ) did not immediately respond to Reuters' request

for comments.