I've had US CBP (not ICE) agents meeting planes, confirming whether you are US citizen/permanent resident, or otherwise. Showing a passport or green card would suffice, as they don't confirm the ID page. Often they have a list of person(s) of interest, but it's not UA specific.
Also, FWIW, US CBP is responsible for immigration laws and procedures at borders, including airports. ICE is responsible for enforcing immigration laws within the US border, not at the border.