Iran's Revolutionary Guard on Saturday threatened to avenge the killing of its top general, saying it would go after everyone responsible for the January U.S. drone strike in Iraq.

The guard's website quoted Gen. Hossein Salami as saying, "Mr. Trump! Our revenge for martyrdom of our great general is obvious, serious and real."

President Trump warned this week that Washington would harshly respond to any Iranian attempts to take revenge for the death of Gen. Qassem Soleimani, tweeting that "if they hit us in any way, any form, written instructions already done we're going to hit them 1000 times harder."

The president's warning came in response to a report that Iran was plotting to assassinate the U.S. ambassador to South Africa in retaliation for Soleimani's killing at Baghdad's airport on January 3.

"We took out the world's number one terrorist and the mass murderer of American troops and many, many troops and many people all over the world," Trump said. "Qasem Soleimani is dead. He's dead. Bad guy. Bad guy. Very bad guy."

Salami had denied the report of an Iranian plot to assassinate Ambassador Lana Marks but made clear that Iran intends to avenge the general's death.