Secretary of state mike Pompeo said Tuesday the U.S. is now focused on undermining Iran’s capabilities amid new reported threats that Tehran plan to assassinate U.S. diplomats – a shift from prior assertions that President Donald Trump’s decision to kill influential Iranian military leader Qassem Soleimani had “re-establishing deterrence” against the regime in Tehran.

“The Iranians didn’t need an action by the U.S. to conduct assassination campaigns around the world,” Pompeo said at an event organized by the Atlantic Council. “What we have done is strive to build out a set of understandings that denies the regime capabilities.”

Pompeo was responding to a report first in Politico over the weekend, citing unnamed intelligence officials, that Iran is considering a targeted killing of U.S. Ambassador to South Africa Lana Marks – a longtime associate of Trump’s – in retaliation for the early January U.S. drone strike that killed Soleimani outside Baghdad International Airport, along with an influential pro-Iranian Iraqi militia leader.

The fact such sensitive intelligence became public has led many to believe that at least some element of the Trump administration saw the leak as an effective way to warn Iran against pursuing such action.

Trump in a tweet late Monday night cited the press reports and issued a new warning against Tehran: “Any attack by Iran, in any form, against the United States will be met with an attack on Iran that will be 1,000 times greater in magnitude!”

The Trump administration has shifted its justification for the provocative decision to kill Soleimani multiple times since the Jan. 3 strike. Officials first claimed the move was designed to stop an attack against unspecified American interests that Soleimani himself was orchestrating. That changed when military officials revealed they believed some sort of attack would take place but that they did not know when or where, or against what or whom. Pompeo himself, days after the strike, backed away from claims of an imminent attack and rather claimed it was in response to a pattern of behavior by Soleimani and other Iranian leaders.

A week later Pompeo explained that the strike was designed to establish “real deterrence” against Iran due to its “malign activity.”

“President Trump and those of us in his national security team are re-establishing deterrence – real deterrence ‒ against the Islamic Republic of Iran,” Pompeo said in a speech on Jan. 13.

Trump himself muddied the rationale behind killing Soleimani in his late-night tweet on Monday, attributing it to “his planning a future attack, murdering U.S. Troops, and the death & suffering…caused over so many years.”

Iran has in recent months feared its response to the killing of the influential leader, who oversaw Iran’s vast networks of proxy forces around the globe and was seen by many in Iran as a figurehead of its revolutionary government, has been insufficient and that it needs to exact a more powerful form of retaliation to maintain its legitimacy.