WASHINGTON (Reuters) – The United States will use sanctions against those behind cyber attacks that target transportation systems or the power grid, the White House said on Tuesday, citing Russia and China as increasingly assertive and sophisticated cyber operators.

The sanctions will be used “when the conditions are right and when actions will further U.S. policy,” White House counter terrorism adviser Lisa Monaco said in prepared remarks to a cyber security conference.

Monaco cited an “increasingly diverse and dangerous” global landscape in which Iran has launched denial-of-service attacks on U.S. banks and North Korea has shown it would conduct destructive attacks.

“To put it bluntly, we are in the midst of a revolution of the cyber threat – one that is growing more persistent, more diverse, more frequent and more dangerous every day,” she said.

The United States is working with other countries to adopt voluntary norms of responsible cyber behavior and work to reduce malicious activity, she said. At the same time, it will use an executive order authorizing sanctions against those who attack U.S. critical infrastructure.

Monaco introduced a new directive from President Barack Obama that establishes a “clear framework” to coordinate the government’s response to cyber incidents.

“It will help answer a question heard too often from corporations and citizens alike – ‘In the wake of an attack, who do I call for help?'” she said.

(Reporting by Doina Chiacu; Editing by Jonathan Oatis)