Executive branch
As best as I can tell, the Supreme Court, which is a federal court, settles disputes between neighboring states.
According to Article III, Section 2 of the Constitution, the US Supreme Court settles disputes between states.
use a book smart a$$
Customs Court
The Judicial branch settles court cases (disputes between individuals). That is not their only job though. They also interpret how the law is to be upheld and carried out.
Supreme Court
Mediator
The Supreme Court settles the disputes in connection with the election of the vice president and the president . Its verdict is final.
adjudication.
administrative adjudication
The Supreme Court
The Supreme Court of India