PRAGUE (AFP) - US Secretary of State Condoleezza Rice signed Tuesday what she called a "landmark" missile defence deal with the Czech Republic that drew immediate fire from Russia. The accord permits the siting of a tracking radar station on Czech soil as part of an extended US missile shield that Washington says is necessary to ward off potential attacks by so-called "rogue" states such as Iran. "It's truly a landmark agreement," Rice said after signing the accord with Czech Foreign Minister Karel Schwarzenberg. "It is an agreement that is befitting for friends and allies who face a common threat in the 21st century." During her talks in Prague, Rice charged that Iran's work to build longer-range missiles was proceeding "apace" while at the same time it was defying international calls to halt sensitive nuclear technology. "Ballistic missile proliferation is not an imaginary threat," the top US diplomat warned. Rice also reiterated Washington's position that the radar station was not aimed at Russia and instead served as a "building block" not just for Czech and US security but for the "international community as a whole." Czech Prime Minister Mirek Topolanek said the deal reflected a "joint desire to protect the free world". "Georgia is an independent state. It has to be treated like one," Rice added. In its first reaction, Russia threatened to react with "military resources" if a US anti-missile shield is set up near its borders, according to a Foreign Ministry statement. "If a US strategic anti-missile shield is deployed near our borders, we will be forced to react not in a diplomatic fashion but with military resources." "There is no doubt that the grouping of elements of the strategic US arsenal faced towards Russian territory" could lead Moscow to "take adequate measures to face the threats to its national security," it added. Earlier,  an unnamed senior Russian Foreign Ministry official quoted by Interfax news agency warned that the deal did not enhance security but "complicates security issues on a global scale." "The step that has been taken... in our view does not enhance security on the European continent. Moreover, it complicates security issues on a global scale," the official said. Russia will no longer consider earlier US offers to assuage Moscow's concerns about missile defence, the Russian official said. "Even those vague promises regarding measures of trust and oversight, which were made by our American partners, have been effectively nullified," he was quoted as saying. In Prague, protesters from Greenpeace who fear the missile shield will trigger a new arms race, unrolled a massive image of a target across city's skyline ahead of Rice's arrival.