Boris Johnson has said General Qasem Soleimani, killed by a US drone strike last week, had “the blood of British troops on his hands”.
He told the Commons the Iranian general was also responsible for a string of attacks on innocent civilians but called for “urgent de-escalation”.
He warned Iran not to repeat “reckless” attacks after ballistic missiles were fired at Iraqi air bases earlier.
Iran’s Revolutionary Guard said they were in response to Soleimani’s death.
In his first Prime Minister’s Questions since Parliament returned from its Christmas break, Mr Johnson said there were no UK casualties.