The news came as the Polish head of state, Andrzej Duda, was on an official visit to Washington, where he was scheduled to meet US leader Donald Trump.
Amid fears of Russian aggression, the authorities in Warsaw have been making intense efforts to secure a boosted American troop presence in Poland, which lies on the eastern flank of NATO.
'New chapter in military cooperation'
Ahead of talks with Trump, Duda told journalists on Wednesday: "This is an agreement which - I hope - will in a sense open a new chapter in our military cooperation, but I also hope that it will do so in other fields too.”
Krzysztof Szczerski, chief of staff to the Polish head of state, told reporters in Washington: "This will be a very good and very fruitful day, because it will change the shape of both Polish-American military cooperation and cooperation on energy issues.”
He added: “It will also change issues that lead to Poland acquiring the status of a country with visa-free travel to the US.”
Szczerski told reporters earlier this week that the American troop presence in Poland "will be increased both in terms of quality and quantity."
He said on Monday that Warsaw and Washington had completed negotiations on a political deal, adding: “The presidents will decide during talks … whether this agreement satisfies them.”
Following Moscow's annexation of the Crimea region of Ukraine in 2014, NATO decided at a Warsaw summit in July 2016 to deploy four rotating multinational battalions to Poland and the Baltic states.
Distrustful of Russia, its giant neighbour to the east, Poland has in recent months been engaged in a flurry of diplomatic activity aiming to secure more US troops, a move it sees as a further security guarantee.
During their White House talks, Duda and Trump were also expected to discuss energy cooperation, including more deliveries of US liquefied natural gas (LNG) to Poland as part of efforts by Warsaw to diversify supplies and bolster energy security by becoming independent of Russian gas, public broadcaster Polish Radio’s IAR news agency reported.