The protocol requires signatories to let the international court make the final decision when detained foreigners say they have been illegally denied access to a diplomat from their country.
Activist groups have widely used the protocol - which was first proposed by the United States - to fight the cases of foreigners on death row in US jails.
The US move, confirmed by Secretary of State Condoleezza Rice during a visit to Mexico, followed a 28 February decision by the world court that 51 Mexicans on death row in US jails should get a new hearing.
President George Bush has decided the US will comply with the ruling and review the 51 cases, Rice said. But the withdrawal will mean that Washington does not have to bow to the international court in such a case again, experts said.
"We remain committed and parties to the Vienna Convention which includes consulate notification," Rice said. "We consider consulate notification extremely important."
The United States proposed the protocol in 1963 and ratified it in 1969 with the rest of the Vienna Convention on Consular Relations.
Rice says rights of consulate
notification will stay
The optional protocol lets the International Court of Justice intervene when suspects are denied the right to see a home-country diplomat when jailed abroad.
US State Department deputy spokesman Adam Ereli made it clear that Washington was angered by the ruling on the Mexicans.
"The decision that the ICJ handed down is a decision, frankly, that we don't agree with," said Ereli.
Ereli also highlighted how 70% of countries that are signatories to the Vienna Convention have not signed up to the optional protocol.
"I don't think anybody should conclude by our decision to withdraw from the optional protocol that we are any less committed to the international system or that we are in any way walking back from international commitments," he emphasised.
"I don't think anybody should conclude by our decision to withdraw from the optional protocol that we are any less committed to the international system or that we are in any way walking back from international commitments"
Adam Ereli, deputy spokesman,
"The reason is because we see the optional protocol being used by people or going in directions that was not our intent in getting involved."
Withdrawing from the protocol could become a new move that will be seized upon by critics who say the United States is isolationist, even though Bush has recently emphasised the need for international cooperation.
Bush was widely criticised during his first term for rejecting the Kyoto international treaty on the environment.
The Bush administration also refuses to recognise the authority of the International Criminal Court, saying it might interfere with global peacekeeping obligations and could be politicised.
It has pressed for bilateral agreements that guarantee US soldiers cannot be extradited to The Hague if they are prosecuted for genocide, crimes against humanity or war crimes.