Obama's lack of response may have emboldened Russia election meddling - former officials

FILE PHOTO - U.S. President Barack Obama delivers a speech on the opening day of the World Climate Change Conference 2015 (COP21) in Le Bourget, near Paris, France, November 30, 2015. REUTERS/Stephane Mahe Picture Supplied by Action Images

WASHINGTON (Reuters) - Russia may have stepped up efforts to meddle in the 2016 U.S. election after President Barack Obama's administration did not retaliate strongly to reports of its activities, former aides to the Democratic president told U.S. senators on Wednesday.

Victoria Nuland, a top State Department official dealing with Russia under Obama, told the Senate intelligence committee that Moscow seemed to have slowed its influence campaign after Obama made "a stern and personal warning" to Russian President Vladimir Putin in September 2016.