US President Donald Trump threatened "major retaliation" Sunday (January 5th) if Iran attempts to avenge the killing of Islamic Revolutionary Guard Corps Quds Force (IRGC-QF) commander Qassem Soleimani.
The threat came as Iran announced it was further reducing compliance with a tattered international nuclear accord, ending limitations on numbers of centrifuges used to enrich uranium.
The latest blow to the accord, which was meant to ensure Iran did not develop a nuclear weapon under cover of its nuclear industry, deepened the regional crisis set off by Friday's killing of Soleimani in Baghdad.
"If they do anything there will be major retaliation," Trump said.
The US president had already threatened bombing of 52 unspecified targets in Iran if Tehran attacked US troops and interests in the region.
Threats and revenge calls
Soleimani was one of Iran's most popular public figures, seen as a hero of the 1980-88 Iran-Iraq war.
He was also the key figure behind Iran's network of proxy militias and alliances across the region where Iran is in often deadly rivalry with US allies.
Iran's supreme leader Ali Khamenei has vowed "severe revenge".
What that will look like is the subject of heated speculation in the Pentagon and the White House. Analysts say Iran may be limited in its room for manoeuver if it wants to avoid full war with the far more powerful US.
But a former head of the IRGC threatened on Sunday to turn the Israeli cities of Haifa and Tel Aviv "to dust" if the US attacks targets in Iran.
And Khamenei's military advisor, Brig. Gen. Hossein Dehghan, told CNN that Iran's response to the assassination "for sure will be military and against military sites".
Pompeo defends decision
US Secretary of State Mike Pompeo on Sunday defended the decision to kill Soleimani while insisting that any further US military action against Iran would conform to international law.
He said Iran will probably try to attack US troops.
"We think there is a real likelihood Iran will make a mistake and make a decision to go after some of our forces, military forces in Iraq or soldiers in north-east Syria," he told Fox News in remarks aired Sunday.
"It would be a big mistake for Iran to go after them," Pompeo said.
The US has about 60,000 troops in the region, including around 5,200 in Iraq. Washington ordered thousands more soldiers to the Middle East on Friday after Soleimani's killing.
"We're preparing for all kinds of various responses," including cyber attacks, Pompeo said.
Britain will not lament
Britain will not lament the death of Soleimani, Prime Minister Boris Johnson said Sunday, though he warned that reprisals would lead to greater violence.
In his first intervention on the escalation of tensions in the Middle East, Johnson said he had spoken Sunday with Trump, French President Emmanuel Macron and German Chancellor Angela Merkel.
He said he would speak to other leaders in the coming days.
"Gen. Qassem Soleimani posed a threat to all our interests and was responsible for a pattern of disruptive, destabilising behaviour in the region," Johnson said.
"Given the leading role he has played in actions that have led to the deaths of thousands of innocent civilians and Western personnel, we will not lament his death," he added.
"It is clear however that all calls for retaliation or reprisals will simply lead to more violence in the region and they are in no one's interest."