US President Donald Trump said Thursday that the United States and Poland had made significant progress toward establishing a permanent American military base in Poland, according to France 24. He said the possible site would be announced soon, describing the move as an important development for the two countries’ alliance.

Trump credited Polish President Karol Nawrocki with supporting the initiative and said the project would represent a historic step in US-Polish relations. Nawrocki said Poland was prepared to continue strengthening defense cooperation and that his government would seek the best possible location for the proposed base.

The announcement comes while the Trump administration is conducting a formal review of the US military presence in Europe. That review has raised concerns among American allies that Washington could reduce its forces in some European countries, France 24 reported.

Poland, which borders Ukraine and Russia and lies on NATO’s eastern flank, has sought a stronger US military presence. The country spends about five percent of its gross domestic product on defense, according to the supplied source. Nearly 10,000 US troops are currently stationed there, although they are largely deployed on a rotational basis rather than permanently.

Polish Deputy Defense Minister Pawel Zalewski said in August that Warsaw and Washington were discussing the creation of a permanent US base. He said the initial stage of the process had been completed and that the political commitment to closer cooperation had already been expressed.

The proposal is also being discussed amid wider tensions over defense spending and access to military facilities in Europe. France 24 reported that Washington has criticized some European countries over their refusal to allow US forces to use NATO bases during the war with Iran. NATO allies agreed at a summit in The Hague to allocate at least five percent of GDP to security spending by 2035, including 3.5 percent for military expenditure.