President Donald Trump warned Iran on Wednesday that the U.S. was preparing for another night of strikes, just hours after he said the ceasefire was over because of Iranian attacks.

A day after assaults on commercial shipping escalated into an exchange of fire on Iranian and U.S. military targets, Trump renewed his past threats to strike Iran’s civilian infrastructure, including electric plants and desalinization plants, and to seize the oil-production hub of Kharg Island.

“We hit them very hard last night,” Trump said when asked about a possible return to hostilities. “We’ll probably hit them hard again tonight.”

Speaking on the sidelines of a NATO summit in Ankara, Turkey, Trump said the strikes are continued retaliation for Iranian attacks on commercial ships in the Strait of Hormuz.

“They are behaving very badly,” he said of Iran, accusing the country of launching drones and a missile at ships. After three tankers were hit Tuesday, the U.S. launched strikes on Iran, and Iranian forces retaliated by attacking American military sites in the Gulf.