Keeping in mind that lots of countries have strict laws about which 'strangers' can and which cannot enter the concerning countries, how would those countries act in (the imaginary) case aliens from outer space came to our earth thus to one of those countries?

With ‘strangers’ I mean those people from countries other than the nationals from the country that the stranger wants to enter (for whatever reason).
Would, for example, the Netherlands, or Denmark, or the USA enforce the same rigid, to me laws concerning strangers/aliens/refugees to judge ‘space aliens’?
I can imagine that, assuming that the aliens are friendly and have no harmful intentions, (some) countries would like to welcome them, because they are curious or they want to research them, but, if so, would that not be unfair to the ‘human aliens’?
Or are those countries going to say: “Sorry aliens, we have strict rules where it concerns entering our nation, so would you be so kind and leave.”?