The statement by Gen. Anatoly Nogovitsyn is the strongest threat that Russia has issued against the plans to put missile defense elements in former Soviet satellite nations.
Poland and the United States on Thursday signed a deal for Poland to accept a missile interceptor base as part of a system the United States says is aimed at blocking attacks by rogue nations. Moscow, however, feels it is aimed at Russia's missile force.
"Poland, by deploying (the system) is exposing itself to a strike — 100 percent," Nogovitsyn, the deputy chief of staff, was quoted as saying.
He added, in clear reference to the agreement, that Russia's military doctrine sanctions the use of nuclear weapons "against the allies of countries having nuclear weapons if they in some way help them." Nogovitsyn that would include elements of strategic deterrence systems, he said, according to Interfax.
At a news conference earlier Friday, Nogovitsyn had reiterated Russia's frequently stated warning that placing missile-defense elements in Poland and the Czech Republic would bring an unspecified military response. But his subsequent reported statement substantially stepped up a war of words.
U.S. officials have said the timing of the deal was not meant to antagonize Russian leaders at a time when relations already are strained over the recent fighting between Russia and Georgia over the separatist Georgian region of South Ossetia.
Russian forces went deep into Georgia in the fighting, raising wide concerns that Russia could be seeking to occupy parts of its small, pro-U.S. neighbor, which has vigorously lobbied to join NATO, or even to force its government to collapse.
Under the agreement that Warsaw and Washington reached Thursday, Poland will accept an American missile interceptor base.
"We have crossed the Rubicon," Polish Prime Minister Donald Tusk said, referring to U.S. consent to Poland's demands after more than 18 months of negotiations.
Washington says the planned system, which is not yet operational, is needed to protect the U.S. and Europe from possible attacks by missile-armed "rogue states" like Iran. The Kremlin, however, feels it is aimed at Russia's missile force and warns it will worsen tensions.
In an interview on Poland's news channel TVN24, Tusk said the United States agreed to help augment Poland's defenses with Patriot missiles in exchange for placing 10 missile defense interceptors in the Eastern European country.
He said the deal also includes a "mutual commitment" between the two nations to come to each other's assistance "in case of trouble."
That clause appeared to be a direct reference to Russia.
Poland has all along been guided by fears of a newly resurgent Russia, an anxiety that has intensified with Russia's offensive in Georgia. In past days, Polish leaders said that fighting justified Poland's demands that it get additional security guarantees from Washington in exchange for allowing the anti-missile base on its soil.