PARIS — Cyberspace faces an approaching risk of ‘‘permanent war’’ between states and criminal or extremist organizations because of increasingly destructive hacking attacks, the head of the French government’s cybersecurity agency warned Thursday.

In an interview, Guillaume Poupard lamented a lack of commonly agreed rules to govern cyberspace.

‘‘We must work collectively, not just with two or three Western countries, but on a global scale,’’ he said. “With what we see today — attacks that are criminal, from states, often for espionage or fraud but also more and more for sabotage or destruction — we are getting closer, clearly, to a state of war, a state of war that could be more complicated, probably, than those we’ve known until now.’’

His comments echoed testimony from the head of the US National Security Agency, Admiral Michael Rogers, to the Senate Armed Services Committee on May 9. Rogers spoke of cyber effects being used by states to maintain the initiative just short of war.

“Cyber war is not some future concept or cinematic spectacle,’’ Rogers said. “It is real and here to stay.’’

Said Poupard: ‘‘The most nightmare scenario, the point of view that Rogers expressed and which I share, would be a sort of permanent war — between states, between states and other organizations, which can be criminal and terrorist organizations — where everyone will attack each other, without really knowing who did what. A sort of generalized chaos that could affect all of cyberspace.’’

‘‘If you start to accuse one country when in fact it was another country . . . we’ll get international chaos,’’ Poupard said. ‘‘We’ll get what we all fear, which is to say a sort of permanent conflict where everyone is attacking everyone else.’’

ASSOCIATED PRESS