Secretary of State Marco Rubio has directed U.S. diplomats around the world to urge foreign governments to “move expeditiously to diminish the capabilities of Iran and Iran-aligned terrorist groups from attacking our respective nations and citizens” amid an “elevated risk of attack” from the country and its proxies, according to a private cable obtained by ABC News. 

The mandate from the secretary was issued to all diplomatic and consular posts Monday as part of an “action request” labeled “Elevated Concern of IRGC Activity,” referring to Iran’s Islamic Revolutionary Guard Corps.

It instructs U.S. officials to deliver the message above — which is labeled sensitive but unclassified — “at the highest appropriate level” by March 20.  

The Trump administration has been seeking to build international support for its military campaign against Iran, particularly when it comes to assembling a coalition to full open the Strait of Hormuz. President Donald Trump said on Monday that a list of countries that had agreed to help would be announced soon. 

Rubio’s communication to diplomats doesn’t elaborate on the elevated risk of attack from Iran or its proxies, but stresses that a combined approach is the best strategy for offsetting the threat. 

“We assess that the Iranian regime is more sensitive to collective action than unilateral action, and that joint pressure is more likely to compel behavior change by the regime than unilateral actions alone,” the cable says.

“We must act while international attention is focused now to end the Iranian campaign of terror in the Middle East and globally. Do not allow this critical movement to pass,” it says.

ABC News has reached out to the State Department for comment.

The cable also instructs diplomats to deliver other messages, including a reminder of Iranian regime’s long-running efforts to destabilize the Middle East and beyond through its support of  groups including Hezbollah, Hamas and Iraqi militias, as well as the goals of Operation Epic Fury — which it says are to “neutralize Iran’s nuclear program, destroy its ballistic missile program, disrupt its proxy networks, and diminish its naval capabilities.” 

“At post’s discretion, advocacy efforts should be coordinated with Israeli diplomatic counterparts,” the cable says, adding that the talking points “may not be left behind.” 

Additionally, diplomats in countries that have not yet designated the IRGC and Hezbollah as terrorist organizations are directed to encourage their government to “swiftly” do so, providing additional arguments aimed at making the case. 

“Such a designation will intensify the pressure on the Iranian regime and limit its ability to sponsor terror activities across the globe that jeopardizes the safety and security of your populations,” the cable says. 

“The IRGC has directly orchestrated terrorist and assassination plots on foreign soil and engaged in ongoing espionage and influence operations,” it adds. “These plots are intentional acts designed to intimidate populations and inflict harm on your civilians.”