Władysław Kosiniak-Kamysz and his deputy, Magdalena Sobkowiak-Czarnecka, are due to meet the head of the Pentagon, Pete Hegseth.
Speaking to broadcaster TVN24 on Monday, Kosiniak-Kamysz described the agreement as "very important" and said teams from both countries were still finalising it.
Asked whether it would cover missile production, he said that was a matter for the future and would not be announced on Tuesday.
The talks are also expected to cover a planned service centre in Poland for PAC-3 missiles, which are used in US Patriot air defence systems.
Sobkowiak-Czarnecka said in October that it would be the only such facility outside the United States.
Kosiniak-Kamysz, who also serves as deputy prime minister, said servicing and certifying the missiles would matter for the whole of Europe.
He stressed that Poland's main goal on the US military presence was a permanent American base, which he argued would strengthen deterrence and move the country "light years" forward in terms of security on NATO's eastern flank.
"I'm not going there cap in hand," the defence minister added.
"I'm going with huge arguments. We are not Cinderella."
In September, US President Donald Trump said "major progress" was being made towards setting up a US ground forces base in Poland.
He credited Polish President Karol Nawrocki and said a location could be announced soon.
The US is also conducting a six-month review of its military presence in Europe, due to end this year.
Germany, Italy and Spain are expected to be most affected, and some troops could reportedly be moved to NATO’s eastern flank.
The assessment could include a decision on a permanent US ground forces base in Poland.
The visit was originally planned for September, but the meeting with Hegseth was cancelled at the last minute because of a visit to the US by China's leader.
(ał)
Source: PAP