The United States killed top military leader Soleimani outside Baghdad airport in a drone strike on Friday.

In his first intervention on the escalation of tensions in the Middle East, Johnson said he had spoken Sunday with US President Donald Trump, French President Emmanuel Macron and German Chancellor Angela Merkel.

He said he would speak to other leaders in the coming days.

"General Qasem Soleimani posed a threat to all our interests and was responsible for a pattern of disruptive, destabilising behaviour in the region," Johnson said in a statement.

"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.

"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."

Johnson said that following ministerial meetings and further international calls, MPs would be updated on the situation on Tuesday.

Meanwhile London has urged Baghdad to allow international coalition soldiers to stay in Iraq, where the parliament on Sunday pressed the government to oust foreign troops.

The cabinet would have to approve any such decision.

British troops are part of an international coalition of forces stationed in Iraq -- invited by the government in Baghdad in 2014 -- to help fight against the Islamic State (IS) jihadist group.

A British government spokesman said: "The coalition is in Iraq to help protect Iraqis and others from the threat from Daesh (IS), at the request of the Iraqi government.

"We urge the Iraqi government to ensure the coalition is able to continue our vital work countering this shared threat."

Some 5,200 US soldiers are stationed across Iraqi bases to support local troops preventing an IS resurgence.