Johnson's statement is published on the website of the British government.
“Attacking the Al-Taji military base in Iraq is regrettable,” the prime minister said.
He said that British Foreign Minister Dominic Raab discussed this issue with US Secretary of State Mike Pompeo.
“We will continue contacts with our international partners in order to fully find out all the details of this disgusting attack,” Johnson added.
Previously, the Pentagon reported that during the shelling of the Et-Taj military base in Iraq, two US soldiers and another military of the country participating in the Washington-led international anti-terrorist coalition were killed.