US and Poland amend missile defense deal
US Secretary of State Hillary Clinton and Poland’s Foreign Minister, Radek Sikorski, were present at the signing.
Earlier in May, an American "Patriot" anti-missile battery was deployed in Poland about 60 kilometers from Russia's border.
Russia is strongly opposed to the plan and sees it as a threat to its national security.
The USA insists the revision of the anti-missile plan is to account for changes in the nature of the Iranian missile threat and protect the USA and its allies.
At a news conference that followed the signing, Hillary Clinton emphasized that the missile defense system poses no threat to Moscow.
"This is a purely defensive system," Secretary of State said.
Warsaw says the shield will be able to protect all European members of NATO. The country also says Moscow will have the right to inspect the systems.