The US State Department has told Congress that a senior former diplomat faces "serious and credible" threats to his safety over the targeted killing of Iranian general Qasem Soleimani.

Brian Hook, former special envoy for Iran, faced threats after Iran vowed vengeance for a US drone attack that killed Soleimani in Baghdad in 2020.

The Washington Free Beacon said on Wednesday that the State Department delivered an unclassified but non-public assessment to Congress on January 11 about a campaign of public death threats aimed at former president Donald Trump and former top officials.

According to the report, "specific threat persists with respect to former special representative [for Iran] Brian Hook," who was instrumental in the operation to kill Soleimani and was at the helm of maximum pressure campaign on Tehran.

The document, seen by the Washington Free Beacon, does not name the actors behind the threats, describing them only as a "foreign power or the agent of a foreign power", but indicates that Hook has been under the threat since at least January 2021.

Earlier in January, a former Iranian diplomat now teaching at Princeton University touted threats against Hook in a documentary, saying, “An American told me that Brian Hook’s wife had not slept for several days and that she was shaking and crying”.

Iran has vowed revengefor its top military operator outside its borders and listed a host of US and Israeli officials as responsible for carrying out the attack.