As per reports, while US-ally Israel was communicated about the airstrike and Soleimani's killing, the United Kingdom was caught unaware.
British Prime Minister Boris Johnson, reportedly, uttered the four-letter 'F' word in an outburst after learning about the US airstrikes at Baghdad International Airport that killed top Iranian military commander Qasem Soleimani on January 3.
As per reports, while US ally Israel was communicated about the airstrike and Soleimani's killing, the United Kingdom was caught unaware.
The UK has around 400 troops stationed in the Middle East and works alongside US forces in the region.
Meanwhile, according to British media, the British prime minister is being criticised for not cutting short his Caribbean vacation amid Soleimani's killing and escalating tensions between the Middle East and the West.
In Johnson's absence, foreign minister Dominic Raab issued a statement on Soleimani's assassination and called for de-escalation.
"We have always recognised the aggressive threat posed by the Iranian Quds force led by Qasem Soleimani. Following his death, we urge all parties to de-escalate. Further conflict is in none of our interests," Raab said as reported by news agency Reuters.
UK PM Boris Johnson is on a vacation with girlfriend Carrie Symonds in the Caribbean ahead of the resumption of Parliament's winter recess.