Iran has stressed its determination to punish those behind assassination of top counter-terror commander Lieutenant General Qassem Soleimani.

“We will not allow the martyr’s blood to go to waste and those who did it escape punishment," Foreign Ministry spokesman Saeed Khatibzadeh told a virtual news conference in Tehran Monday. 

The Islamic Republic has ceaselessly pursued this matter and will keep doing so through the international channels, he said.

“This is not something that the Iranian government and the establishment could let go by. The US administration is accountable in this regard,” the diplomat added.

Khatibzadeh said the United States committed a monumental strategic mistake by perpetrating the terrorist act. 

“We will not abandon this pursuit until we have taken all those who abetted this [atrocity] or were involved in it, to the altar of justice.”

General Soleimani was the former commander of the Quds Force of Iran’s Islamic Revolution Guards Corps (IRGC). He was admired as the Middle East's most potent counter-terrorism combatant, with a unique charisma.

He was Iran’s lead military advisor helping in Iraq and Syria defeat foreign-backed takfiri terrorists, chiefly Daesh in late 2017. 

He was assassinated in a US drone strike in Baghdad on January 3 during an official visit. His Iraqi trenchmate Abu Mahdi al-Muhandis, deputy commander of Hashd al-Sha’abi anti-terror force, was also killed along with their other companions when their convoy was hit.

Khatibzadeh touched on Tehran’s efforts to present the enormity of the atrocity to the world and bring the perpetrators to justice.

The Islamic Republic, he said, has registered more than five letters and official notes with the United Nations and used its diplomatic missions to introduce General Soleimani and the nature of his mission to the world.

The official said Agnes Callamard, the UN special rapporteur on extrajudicial, summary or arbitrary executions, denounced the assassination as an act of terrorism earlier this year, only after Iran's Foreign Ministry presented the world body with a detailed account of the circumstances surrounding the terrorist act.

Tehran will follow up on its efforts in this area across international courts and tribunals, he added.

Apart from commanding the Quds Force, General Soleimani served as a “pillar of regional stability" who contributed most to the realization of peace and maintaining interaction with different leaders of the region, Khatibzadeh said. 

The spokesman touched on General Soleimani’s famous “We are a nation of martyrdom” remarks, saying extremism cannot be defeated unless through the courage and pure blood of those confronting it.

Khatibzadeh further warned the outgoing administration of President Donald Trump against any new adventurism, saying the US would bear responsibility for any act of mischief. 

"We are not looking for tension, but we would defend Iran's national interests with all our might," he said, adding the Islamic Republic has given the message that it would hold "the US and other plotters" responsible for any mischievous act against it. 

Khatibzadeh said he hoped level heads would prevail at the White House over warmongering elements during the final days of the Trump administration.