NEW : Polish , Czech leaders cautiously optimistic about U.S. leadership . Russian president : ` ` We appreciate the responsible leadership '' of Russia " . NSA chief Robert Gates denies U.S. ` ` scrapping '' missile defense . Czech Prime Minister Jan Fischer issued a statement saying that Obama told him in a Wednesday phone call that the United States would shelve its plans . Change of leadership does creates diplomatic problems for Russia , Gates says .
NEW : Polish , Czech leaders cautiously optimistic about U.S. leadership . Russian president : ` ` We appreciate the responsible leadership '' of Russia " . NSA chief Robert Gates denies U.S. ` ` scrapping '' missile defense . Change of leadership does creates diplomatic problems for Russia , Gates says .