Barbara Bartkowska said Klich would meet with U.S. Secretary of Defense Robert Gates, and negotiations would focus on the deployment of a U.S. missile defense base in Poland and the International Security Assistance Force mission in Afghanistan.
Washington wants to place 10 missile interceptors in Poland and a radar in the neighboring Czech Republic, purportedly to counter a missile threat from Iran and other "rogue" states.
Klich said ahead of his visit, which started on Monday, that Washington has to provide greater security guarantees for Poland if it wants the country to accept 10 interceptor missiles. Many Poles believe the missiles could make Poland a target for these very same "rogue states."
He said it would be "very difficult" to convince Poles to support the program without additional security measures.
Moscow fiercely opposes the U.S. plans, saying the European shield would destroy the strategic balance of forces and threaten Russia's national interests.
Polish Prime Minister Donald Tusk earlier said that Poland had not yet received guarantees from Washington that the deployment of the missiles would enhance the country's security.
Tusk, who took office in November last year and has a more cautious approach to the U.S. proposal than his predecessor Jaroslaw Kaczynski, said Poland and the Czech Republic would coordinate their activities concerning missile defense negotiations with the U.S.
Last Thursday, Czech Prime Minister Mirek Topolanek held a meeting with Tusk in Prague. The Czech official said his government would submit to parliament in April a missile defense bill that includes the placement of a U.S. radar on the country's territory.