Actually they do.
Under the 1951 United Nations Convention Relating to the Status of Refugees and the 1967 protocol, and adopted into U.S. law, the U.S. must recognize refugees that fear persecution and are not able to get help from their home country.
This law was created by the UN of which your country was the founding and still the most powerful member.
The very UN your country uses to sanction weak countries.
You -- just like others -- are so eager to jump on the anti-US bandwagon that you ended up tripping and fell on your own face.
I bet that you -- just like others --
DID NOT do even basic research into the subject.
https://www.unhcr.org/en-us/3b66c2aa10
https://www.refworld.org/docid/3b20a3914.html
…the term “refugee” shall apply to any person who: …owing to a well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group or political opinion, is outside the country of his nationality and is unable, or owing to such fear, is unwilling to avail himself of the protection of that country…
Economic hardships due to governmental incompetence does not make one a refugee when desiring to leave that condition.
The problem here is the interpretation of the word 'refugee'. The common understanding of 'refugee' is usually that of being a consequential victim of a war, either civil or international. The next common understanding is of the paragraph (highlighted) above when there is no war but a person is persecuted for having certain characteristics and/or traits.
If you are being persecuted because of your brown skin, there is no debate on admittance. Come on in...
But if your country is mismanaged and the consequences are widespread, there is no particular target for any kind of persecution. Black, white, or brown skin. Christians, Buddhists, Muslims, atheists. Man, woman, old, young. All are being affected.
So for this issue for US at this time, this is not about human rights but about breaking the laws.