Those provisions put the United States in direct and immediate breach of its obligations under the UN Universal Declaration of Human Rights:
Article 14.(1) Everyone has the right to seek and to enjoy in other countries asylum from persecution. (2) This right may not be invoked in the case of prosecutions genuinely arising from non-political crimes or from acts contrary to the purposes and principles of the United Nations.The United States is also a party to the UN Convention relating to the Status of Refugees, by way of being a party to its 1967 Protocol, which indicates practical steps in the implementation of Article 14 of the Universal Declaration of Human Rights. The obligations under this Convention are summarised at the Wikipedia page . It is quite clear under the Convention that any decision not to accept the refugee status of an asylum seeker should be an individual decision and not a generalised one applied to whole groups or categories. It is also clear that particular measures should not be based on the nationality or country of origin of a refugee. The executive orders, which deny entry to the United States for refugees from particular countries, clearly prevent those refugees from exercising a right that is theirs under international legal provision.
The ethical principle underpinning both the Universal Declaration and the Convention is that of respect for the dignity, and therefore the rights, of persons precisely as persons and without regard to any other circumstance that may accrue to persons in particular situations. Poor Donald seems to be somewhat inconsistent here - defending the dignity of the unborn (cf Article 3 of the Universal Declaration) but treating with disdain the dignity of the refugee.
The justification on the grounds of national security is as blatantly false as is poor Donald's claim of electoral fraud. We shouldn't buy it. That the United Kingdom will soon welcome poor Donald on a state visit is embarrassing to say the least. But Catholics will be caught in a dilemma - we might want to protest his steps with regard to refugees, but will find ourselves alongside those who also want to protest his steps with regard to abortion.