When coast guards would fight in Azur Lane

In Azur Lane, how likely would the United States Coast Guard be to fight the Sirens?

If a separate coast guard exists in Azur Lane, its forces would be expected to join the fight when an enemy approaches.

The question assumes that coast guards could have ship-girl counterparts in Azur Lane. One response doubts that a separate United States Coast Guard would exist in the setting. If it does, another response expects its forces to join combat when an enemy approaches. The argument is that every available unit should help counter the threat, including forces with other peacetime duties.