The Polish government’s request for a permanent U.S. base in their country — a facility the Poles have dubbed “Fort Trump” — is moving closer to approval, a Pentagon official said Wednesday.

U.S. and Polish defense officials are meeting in Warsaw this week to negotiate the final terms of the basing deal.

Poland has agreed to contribute $2 billion and “perhaps more” to the construction and operation of the base, said Kathryn Wheelbarger, acting assistant secretary of defense for international security affairs.

“We’ve come forward with what we think is a very serious and robust offer and we’re just working out some of the technicalities this very week,” she told the House Armed Services Committee. “We hope to have a solid foundation coming out of this meeting today.”

The Polish government initially floated the request for a permanent U.S. base last summer, and Polish President Andrzej Duda pitched the plans to President Trump in a September visit to Washington.

The deal to build “Fort Trump” could come with policy strings and geopolitical implications. Its bilateral nature would represent a fundamental change in the U.S. military’s traditionally broader approach toward European defense.

Establishing the base would also deepen tensions between Washington and Moscow because Warsaw has made no secret of its desire to use the facility as a bulwark against potential Russian military aggression.

General Curtis Scaparrotti, commander of the U.S. European Command and NATO Supreme Allied Commander Europe, said he welcomed the possibility of a permanent base in Poland.

He told the committee “a more permanent base is helpful because of the relationships they build and the mission they have,” but explained he is “perfectly content with the large forces that we’re rotating today.”

As the U.S. and Poland work on finalizing a deal, which may be just “six months to a year” away, according to Ms. Wheelbarger, it remains unclear whether the $2 billion offer would be subject to President Trump’s new “cost plus 50” funding formula which calls on allies to pay the full cost of hosting U.S. troops, plus fifty percent.