The US had said in June it would store battle tanks, infantry fighting vehicles and other heavy weapons for as many as 5,000 American troops in several Baltic and eastern European countries.
"We expect this deployment to take place in mid-2016," Polish Defence Minister Tomasz Siemoniak told the local news agency PAP.
He said two locations for the weaponry had been identified in the west and northeast of the country following talks with the US but would not specify the exact locations.
The deployment of weaponry will represent the first time since the Cold War that the US has stationed such equipment in NATO members that were once under Soviet sway.
Russian President Vladimir Putin responded to the US plan by announcing in June that Moscow would in turn expand its nuclear arsenal and accused NATO of "coming to our borders".
Poland and other countries in eastern Europe have been rattled by Russia's actions in Ukraine, where pro-Moscow separatists have been fighting Kiev's forces since April 2014.