For your information: The Norwegian Government refers to it as a letter from the President of the United States to the Prime Minister of Norway. So no, this is not a random tweet.
If I remember correctly, the message was originally sent as a text message, but when a head of state sends a written message to another head of state, and that message is then circulated as an official FYI to the sender’s ambassadors, it is widely regarded as official communication.
The article itself is an opinion piece, yes, but the letter has been extensively reported across Europe and internationally. I could just as well have referenced one of those reports.
If I remember correctly, the message was originally sent as a text message, but when a head of state sends a written message to another head of state, and that message is then circulated as an official FYI to the sender’s ambassadors, it is widely regarded as official communication.
The article itself is an opinion piece, yes, but the letter has been extensively reported across Europe and internationally. I could just as well have referenced one of those reports.