The United States may strike Iran again "hard tonight," US President Donald Trump told reporters here Wednesday on the sidelines of the NATO summit.

Trump said Tehran has been "behaving very badly" regarding a recently signed peace memorandum of understanding, citing recent drone and missile attacks as well as "assaults" on U.S. ships.

The United States could resume a naval blockade against Iran in the Strait of Hormuz and possibly take over Iran's Kharg Island, he said.

He added that the United States has lost 200 people during the latest conflict in the Middle East.

Still, Trump suggested that the US negotiation team might continue its efforts.

The remarks came as the United States and Iran traded fresh attacks from Tuesday night to Wednesday, marking a new round of escalation.

The United States has launched strikes against 80 Iranian targets allegedly in response to recent Iranian attacks on commercial vessels transiting the Strait of Hormuz. Later, Iran's Islamic Revolution Guard Corps attacked 85 US military sites in Bahrain and Kuwait.