Russia may be readying for new Ukraine offensive - NATO commander

U.S. Air Force Gen. Philip Breedlove, commander of the U.S. European Command and Supreme Allied Commander for Europe, arrives to testify before a Senate Armed Services Committee hearing on Capitol Hill in Washington, April 30, 2015. REUTERS/Jonathan Ernst

WASHINGTON (Reuters) - Russia's military may be taking advantage of a recent lull in fighting in eastern Ukraine to lay the groundwork for a new military offensive, NATO's top commander told the U.S. Congress on Thursday.

U.S. Air Force General Philip Breedlove, the NATO supreme allied commander, said Russian forces had been seeking to "reset and reposition" while protecting battlefield gains, despite a fragile ceasefire agreed in February.