"I don’t want to comment on the intelligence," Pompeo told Atlantic Council President and CEO Frederick Kempe during a virtual discussion, but did not rule the prospect of a clandestine operation.
Pompeo said the Iranians "didn’t need an action by the United States to conduct assassination campaigns around the world" as this has been "their model for 40 years".
A day earlier, US media reported that the United States believes Iran has been plotting to assassinate US Ambassador to South Africa Lana Marks in retaliation for the killing of top Iranian military commander Qasem Soleimani in Iraq earlier this year.
Officials familiar with the situation were cited by media as saying the US government had been aware of a general threat against Marks since the spring and informed her about the threat.
Marks was sworn in as US Ambassador to South Africa in October 2019. She has known US President Donald Trump personally for two decades and officials have speculated that her close ties might have played a role in the plotting of alleged assassination by Iran.
On January 3, a Trump-ordered airstrike killed Soleimani, one of the most prominent military figures in Iran, and several other members of the Iranian Revolutionary Guard Corps on the outskirts of Baghdad. The assassination prompted Tehran to launch missile strikes on US bases in Iraq.