Krzysztof Szczerski, chief of staff to the Polish president, said that Duda and Trump would sign off on the agreement during bilateral talks ahead of a United Nations debate in New York.
Szczerski told public broadcaster Polish Radio on Friday that 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.
Szczerski told Polish Radio that the planned meeting of the two presidents in New York on Monday would include “face-to-face and plenary talks.”
He added that the Polish foreign and defence ministers would also take part in the talks.
The Polish head of state is flying to the United States on Saturday for a five-day visit during which he is scheduled to take part in a UN General Assembly gathering and meet with Polish Americans.
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.