Russia produces as much ammunition in three months as NATO does in a year, NATO Secretary General Mark Rutte has warned. Speaking at the Chatham House think tank in London on Monday, Rutte called on the alliance to urgently ramp up weapons production.

Moscow could send "little green men" to attack the bloc's Eastern flank, said Bruno Kahl, head of Germany's Federal Intelligence Service.

Russia is determined to test the resolve of the NATO alliance, including by extending its confrontation with the West beyond the borders of Ukraine, the Germany's foreign intelligence chief told the Table Media news organization.