United States Citizenship and Immigration ServicesUnited States Citizenship and Immigration Services (abbreviation USCIS) 
a US government organization that is part of the Department of Homeland Security. It is responsible for immigration matters and has the power to decide whether or not someone can become a US citizen, live in the US, or claim asylum (=live in another country because it is not safe to live in your own country).
a US government organization that is part of the Department of Homeland Security. It is responsible for immigration matters and has the power to decide whether or not someone can become a US citizen, live in the US, or claim asylum (=live in another country because it is not safe to live in your own country).