Putin gave the warning during a military parade marking the anniversary of the Soviet victory over Nazi Germany in World War II.
“Besides commemorating those who had defeated Nazism, it was important to stay vigilant and to do everything possible to ensure that the horrors of global war are not repeated,’’ he said.
Putin said fighting for Russia’s security was taking place today in the Donbass in eastern Ukraine.
He justified Russia’s invasion of Ukraine with NATO activities in the country.
He said Russia has pre-emptively repelled the aggression that was the only right decision.
He added that Moscow had repeatedly tried to reach an agreement for an international security solution.
The president said NATO had ignored Russia’s arguments and started to open up Ukrainian territory militarily.
There is no evidence for Putin’s repeated claim of an imminent Ukrainian attack on Russia.
In the past, NATO has participated in military exercises in Ukraine and trained Ukrainian soldiers.