"The elements of missile defense are emerging in Alaska and now in South Korea. Should we look at this passively like in the western part of Russia? Of course no, we are thinking how we should reply to these challenges, this is a challenge for us," Putin said.
The Russian president added that the US missile defense system's continued expansion pushed Russia toward an arms race.
"The situation is exacerbated since it pushes an arms race, creates a new spiral," Putin said at a summit of heads of international news agencies as part of the St. Petersburg International Economic Forum (SPIEF).
The Russian president spoke at a summit of heads of international news agencies as part of the St. Petersburg International Economic Forum (SPIEF), where the Rossiya Segodnya International Information Agency is the official media partner.
The Rossiya Segodnya International Information Agency is the official media SPIEF.