MOSCOW – Russia threatened on Wednesday to deploy missiles to target the U.S. missile shield in Europe if Washington fails to assuage Moscow’s concerns about its plans, a harsh warning that reflected deep cracks in U.S.-Russian ties despite President Barack Obama’s efforts to “reset” relations with the Kremlin.

President Dmitry Medvedev said he still hopes for a deal with the U.S., but he strongly accused Washington and its NATO allies of ignoring Russia’s worries. He said Russia will have to take military countermeasures if the U.S. continues to build the shield without legal guarantees that it will not be aimed against Russia. The U.S. has repeatedly assured Russia that its proposed missile defense system wouldn’t be directed against Russia.