Italy, Denmark, the Netherlands and France on Tuesday backed the UK's proposal for a European naval force to be used at the strait.
The Latvian Defense Ministry says it could take part in the defense coalition; however, Latvia does not have any ships that could be used for the operation.
Iran has detained the British tanker Stena Impero on allegations of failing to respond to distress calls and turning off its transponder after hitting a fishing boat.
There are 23 people of Indian, Russian, Latvian and Filipino nationality in the ship's crew.
The Latvian Foreign Ministry has submitted a note to the Iranian Embassy in Stockholm calling on Iran to release the Latvian citizen. The Latvian national, a man born in 1978, is the chief assistant of the ship's captain.
On July 24 the man, together with the rest of the crew, was allowed to contact his family.