By Humeyra Pamuk WASHINGTON (Reuters) -All signs suggest Russia is on the brink of invading Ukraine, U.S. Secretary of State Antony Blinken said on Sunday, but still vowed that Washington would use every opportunity until the last minute to see if diplomacy would dissuade Moscow from going ahead. Speaking on broadcaster CNN's "State of the Union" show, Blinken maintained Washington's position that the deterrent impact of sanctions would be lost if they are triggered before an invasion despite Ukrainian President Volodymyr Zelenskiy's passionate plea on Saturday to unleash them. "Everything we ...
