Denmarkalso used them and sometimes the Danish version is sold as or confused with the British
Pat.44 canteen.
DANISH/ BRITISH ARMY p44 1944 PATTERN CANTEEN dated 1954 | eBay
As I understand it the unmarked Pat.44 canteen cup which is often found, as per this example in my collection, is thought to be British, which I purchased for the Pat.44 canteen but haven't united the 2 items yet.
It would seem that the Dutch also used them.
Later edit, I found the article which I was thinking of which sheds a bit more light on the unmarked cups, if you scroll down the page.
https://hmvf.co.uk/topic/23124-1944-...er-bottle-cup/