British Prime Minister Boris Johnson has spoken out against US President Donald Trump's threat to bomb 52 Iranian cultural sites if the crisis escalates, in a rare crack in the transatlantic alliance.
"There are international conventions in place that prevent the destruction of cultural heritage," the prime minister's spokesman said.
However, he declined to say whether such an attack would be a war crime – and gave stronger backing to the assassination of Qasem Soleimani than in Johnson's comments on Sunday.
Asked whether the UK accepted Washington's justification for the attack, the spokesman said: "States have a right to take action such as this in self-defence and the US have been clear that Soleimani was plotting imminent attacks on American diplomats and military personnel."
But, asked if the UK would regard attacks on cultural sites as a war crime, the spokesman replied only that details of the international agreement were contained in the 1954 Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict.
Donald Trump on Saturday threatened to hit 52 Iranian sites "very hard" if Iran attacks Americans or US assets after a drone strike that killed Iranian military commander Qassem Soleimani.
Showing no signs of seeking to ease tensions raised by the strike he ordered that killed Soleimani and Iranian-backed Iraqi militia leader Abu Mahdi al-Muhandis at Baghdad airport on Friday, Trump issued the threat to Iran on Twitter.
The strike has raised the spectre of wider conflict in the Middle East.
Convention for the Protection of Cultural Property
The Convention for the Protection of Cultural Property in the Event of Armed Conflict was adopted at The Hague (Netherlands) in 1954 in the wake of massive destruction of cultural heritage during the Second World War. It is the first international treaty with a world-wide vocation focusing exclusively on the protection of cultural heritage in the event of armed conflict.
It covers immovable and movable cultural heritage, including monuments of architecture, art or history, archaeological sites, works of art, manuscripts, books and other objects of artistic, historical or archaeological interest, as well as scientific collections of all kinds regardless of their origin or ownership.