The Optional Protocol to the Vienna Convention on Consular Relations allows the International Court of Justice the right to intervene in the cases of foreigners held in US jails, particularly those denied access to consular officials from their own country.
Some 51 Mexicans on death row in Texas and other states were granted fresh hearings following the intervention of the ICJ last year, leading to friction between the US and Mexico.
"This is a really unexpected and unwelcome precedent, where people who don't like decisions of our state courts can use an international court as a court of appeal," said State Department Deputy Spokesman Adam Ereli.
Initially devised as a way to protect US citizens jailed abroad, Washington used this protocol to sue Iran for taking 52 Americans hostage in 1979.
But Ereli said the comparison was unfair, since adequate legal protections are already in place in the US for Mexican and other foreign defendants, which was not the case in Iran.
"That doesn't make any sense at all. We've got a system of justice that works in the United States. I don't think you should compare it to other countries, like Iran in 1979.
"We have a system of justice that works, we have a system of justice that provides people with due process and review of their cases, and it's not appropriate that there be some international court that comes in and can reverse decisions of our national courts."
Insisting that Washington remained committed to its international obligations despite the withdrawal, he noted that many ICJ member countries not agreed to this part of the convention.