As reported by Censor.NET, he said in an interview with Reuters.
"NATO, mainly this is not a question of money, it is a question of security. Russian aggression demonstrated again there is no other security system but NATO which was effective to stop the aggression," he said.
According to the President, the recent U.S. steps, namely the deployment of U.S. military in Poland and the Baltics, are extremely important for delivering the efficiency of the Alliance. " And to demonstrate its role as a global leader, the U.S. would need to establish trans-Atlantic unity."
Poroshenko said joint global efforts were needed to halt Russian aggression, both military and cyber: "There is a global cyber war of Russia against (the) whole world, there is lots of evidence. This is a global danger and the world should be together to fight this danger."
Ukraine's utility Ukrenerho told Reuters on Wednesday in Kyiv that a cyber attack was behind a Dec 17-18 power blackout in the capital city.
Ukrenerho did not say who was behind the incident, although Ukrainian security services blamed Russian cyber attacks for similar power outages in December 2015. The Kremlin has denied any involvement in cyber attacks on Ukraine.