Defense Secretary James Mattis on Thursday said that there was "very little doubt" Russia has attempted to interfere in democratic elections in the past.
"There is very little doubt that they have either interfered or attempted to interfere in a number of elections in democracies," Mattis said while answering questions at NATO headquarters in Brussels.
Mattis maintained that Russia needs to "live by international law" and "prove itself" when it comes to its international commitments.
"The commitment to Article Five remains rock solid. The message that I brought here about everyone carrying their fair share of burden, of sacrifice to maintain the best defense in the world was very well received. It was not contentious," he said.