The [International] Covenant [on Civil and Political Rights] does not recognize the right of aliens to enter or reside in the territory of a State party. It is in principle a matter for the State to decide who it will admit to its territory. However, in certain circumstances an alien may enjoy the protection of the Covenant even in relation to entry or residence, for example, when considerations of non-discrimination, prohibition of inhuman treatment and respect for family life arise [3] .