LONDON (Reuters) - Britain urged all parties to show restraint on Saturday after the United States killed Iranian military commander Qassem Soleimani in an air strike, but said its closest ally was entitled to defend itself against an imminent threat.

Defence minister Ben Wallace said in a statement that he had spoken to his U.S. counterpart Mark Esper, adding: “We urge all parties to engage to de-escalate the situation.

“Under international law the United States is entitled to defend itself against those posing an imminent threat to their citizens,” he added.