in 60 some years of ‘aliens’, not a single one has landed on the WH lawn and asked to see our leader. If I was a friendly alien, I might want somebody to know that I put a lot of effort into getting to Earth to say hello. And if I was an enemy alien, I wouldn’t care who saw me.
Thats because they met with Truman at Murock AFB (aka Edwards) not the Whitehouse.