U.S. not to change missile defense

The White House on Wednesday said the U.S. will not limit or change its missile defense plans in Europe despite Russias threat to pull out of the START agreement.Spokesman Tommy Vietor told reports the U.S. has been open and transparent with Moscow on its missile defense plans in Western Europe. The U.S. has repeatedly said those plans reflect a growing threat from Iran and would not be directed against Russias nuclear forces.His comments follow Russian President Dmitry Medvedev's assertion Wednesday that Russia would target the U.S. missile shield if Washington fails to assuage Moscow's concerns. Medvedev also warned that Moscow may opt out of the New START arms control deal with the U.S.Vietor says implementation of the new START treaty is going well and the U.S. sees no basis for threats to withdraw from it.