The US has been in talks with Poland and other countries over the possibility of setting up a European base to intercept long-range missiles.
The US has already started testing its own missile defence system
The US is already working on a defence system designed to detect and shoot down missiles fired at North America.
A US official said there had been talks with other countries about establishing such a base to protect Europe as well.
Poland's prime minister said the government would consider whether the idea was good for Poland.
The unnamed Pentagon official, who spoke to news agencies on condition of anonymity, said the talks had been going on since 2002.
"We have the most mature dialogue with Poland because they've expressed continuing interest in the subject," he said. "There are other countries that remain interested in the dialogue on the possible emplacement of interceptors in Europe."
He told AFP that a site similar to the US base in Alaska would help protect the US and Europe from missiles fired from the Middle East or North Africa.
Prime Minister Kazimierz Marcinkiewicz said he wanted to open up the public debate on whether Poland should host a US missile base.
"This is an important issue for Poland, related to our security and to our co-operation with an important ally," he said.
The US official said such a base would not have been conceivable before Poland joined Nato in 1999.