Iran's Justice Minister Ebrahim Raisi warned Trump and anyone involved in the airstrike that killed General Soleimani would be "unsafe on Earth".

"They will have to see heavy revenge," Raisi said at the University of Tehran on Jan. 1, referring to President Donald Trump and US military leaders involved in the January killing of General Qasem Soleimani.

Raisi warned that not even Trump was "exempt from justice" because of his role in the attack on Iranian generals.

"Don't assume that someone, as the president of the United States, who appears to be a murderer or orders a murder, can be exempt from the enforcement of justice. Never," added Raisi.

The warning of the Iranian official issued when January 3 will mark a full year when General Soleimani, the longtime leader of the elite Quds task force, was killed by airstrikes.

Iran's Foreign Ministry on the same day criticized the US on Twitter.

"By carrying out a frantic act of terror against General Soleimani, the United States has violated international law and the United Nations Charter by blatantly violating Iraq's sovereignty," the post said.

At a similar event on the same day, Iranian General Hossein Salami, the top commander of the Revolutionary Guard, said Iran was well prepared to respond to US military pressure as tensions between Washington and Tehran remain.

Earlier this week, the US military sent two B-52 bombers to the Middle East to emphasize commitment to regional security as well as "deterrence of all potential adversaries, marking the third time in 45 days.

Just two days before Christmas, Trump also issued a stern warning to Iran after the US embassy in Baghdad was raided by rockets on December 20.

"Some useful advice to Iran. If an American is killed, I will hold Iran accountable. Think about it," he wrote.