The UK has put the Royal Navy and military helicopters on standby amid rising tensions in the Middle East, Defence Secretary Ben Wallace has said.
The government was putting in place "urgent measures" to protect British nationals and interests in the region, Mr Wallace told the House of Commons.
He said non-essential UK personnel had also been moved out of Baghdad.
His comments come in the wake of the US killing of Iranian general Qasem Soleimani in Iraq on Friday.
Mr Wallace, answering questions from MPs on the growing crisis, reiterated the government's calls for all sides to "de-escalate".
But hours after his statement, the US Department of Defence said
an airbase housing US troops in Iraq had been hit by more than a dozen ballistic missiles.
Iranian state TV said the attack was in retaliation to Soleimani's death.