The "Joint Declaration on Advancing Defense Cooperation" approved by the two leaders includes details of a planned increase in the US military presence and names sites for the stationing of American troops in Poland.
Under the document, a US division headquarters will be established in Poland's western city of Poznań, alongside facilities such as a Combat Training Center for the joint use of the US and Polish armed forces in the northwestern town of Drawsko Pomorskie.
Meanwhile, Wrocław-Strachowice in the southwest of the country will host an aerial port of debarkation to support the movement of forces, and the central town of Łask will host a US Air Force remotely piloted aircraft squadron.
Further sites include Powidz, in the west-centre of Poland, where a combat aviation brigade will be based, together with a combat sustainment support battalion and a special operations forces facility.
Additionally, the southern town of Lubliniec will host a further special operations forces facility.
“They’re going to be building us facilities that I’m sure will be very beautiful,” Trump said during a bilateral meeting with Duda in New York on Monday.
Under the declaration, Poland and the United States pledged to "continue to strengthen" their "strategic and defense relationship" to enhance mutual security and that of the NATO military alliance.
The United States pledged to deploy around 1,000 extra troops to Poland, a staunch military ally fearful of Russia, under a declaration signed by the Polish and US presidents at the White House in June.
Around 4,500 rotating American troops are already stationed in the country on average as part of a NATO force.
The meeting between Duda and Trump on the sidelines of a United Nations gathering in New York on Monday was their ninth during their terms of office, according to Krzysztof Szczerski, chief of staff to the Polish president.
The two presidents were originally scheduled to ink the document in Warsaw earlier this month during a visit by Trump for events to mark the 80th anniversary of the start of World War II.
But Trump cancelled his planned trip to Poland at the last minute, saying he needed to stay and monitor Hurricane Dorian as it approached the southern US state of Florida.
Polish Defence Mariusz Błaszczak said at a press conference with Duda on Monday that the declaration on military cooperation was “historic.”
A beaming Błaszczak added: “This is undoubtedly a great day in terms of Poland’s security, of NATO’s security. This is an important day in terms of Polish history.”
Duda is in the United States on a five-day visit during which he attended a UN climate summit and took part in a debate on religious freedom on Monday.
The Polish head of state is scheduled to address a session of the UN General Assembly on Tuesday.
Source: TVP Info, president.pl