U.S. President Donald Trump said Monday that the American military is intensifying its operations against Iran, warning that a larger phase of action is imminent.

In a nine-minute phone interview with CNN, Trump said the United States is delivering significant blows to Iranian targets but suggested that the most substantial military action has yet to begin.

“We’re knocking the crap out of them,” Trump said. “I think it’s going very well. It’s very powerful. We’ve got the greatest military in the world and we’re using it.”

The president addressed a range of issues during the interview, including the potential duration of the conflict, what he described as unexpected levels of Iranian retaliation, and questions surrounding Iran’s political succession plans.

When asked whether the United States is taking additional steps beyond military action to support the Iranian people in regaining control of their country from the current regime, Trump responded affirmatively.

“We are indeed,” he said, without elaborating. “But right now we want everyone staying inside. It’s not safe out there.”

Trump also cautioned that conditions are likely to deteriorate further.

“We haven’t even started hitting them hard,” he said. “The big wave hasn’t even happened. The big one is coming soon.”