U.S. policymakers are vowing action against Russia.
The White House on Sunday was quick to dismiss the referendum.
The administration called on others in the international community to impose costs on Russia.
The State Department is offering condolences to Cao Shunli's family.
"Clearly he has set the table to his advantage in any negotiation going forward," he said.
“This is a Soviet-style election. We know what the end is going to be,” Durbin said.
“This sham referendum isn’t fooling anyone,” he said.
King said the pilot and the co-pilot “should have been the focus from the start.”
“Putin only understands strength,” Sen. Robert Menendez said.
"We used to call it plebiscite in the days of Hitler and Stalin," he said