Britain on Tuesday said it was suspending military exports to Turkey following its incursion into northeastern Syria, as it carries out a review of arms sales to its NATO ally.
"We will keep our defence exports to Turkey under very careful and continual review," Foreign Secretary Dominic Raab said in a statement to parliament.
"No further export licences to Turkey for items which might be used in military operations in Syria will be granted while we conduct that review."
Ankara's assault against Kurdish forces launched last week has prompted a chorus of international condemnation. Raab said it had "seriously undermined the security and stability of the region".
"This is not the action we expected from an ally, it is reckless, counterproductive, it plays straight into the hands of Russia and the Assad regime," he told lawmakers.
Britain's arms sales suspension follows similar moves by key European and NATO allies, including Germany -- one of Turkey's main arms suppliers -- and France.
Meanwhile, US President Donald Trump warned Monday that Turkey faces imminent sanctions over its actions but also signalled that Washington would avoid any armed conflict with Ankara.
Turkey's President Recep Tayyip Erdogan has said threats of sanctions and arms embargoes by Western powers will not stop the military offensive.
"Those who think they can make Turkey turn back with these threats are gravely mistaken," he said in a televised speech on Sunday.