British Prime Minister Boris Johnson has broken his silence on the U.S. killing of Iran's top military general Qasem Soleimani on Friday, following growing criticism of his failure to comment on the killing – as he continued a luxury Caribbean holiday.

Johnson said the UK "will not lament" the death of Qasem Soleimani, blaming him for "the deaths of thousands of innocent civilians and Western personnel."

But he also said: "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."

After the killing, major countries like Russia, France, Germany, and China have all expressed concerns and called for restraint.

Israel was among the minority that hailed the U.S. action.

In the meantime, NATO has announced an emergency meeting on Monday over the Iran situation.