THE HAGUE - The execution of a Mexican national in Texas last year breached U.S. obligations under international law, the World Court held on Monday.
The court said its 2004 judgment, in which it ordered the United States to review the death sentences of a number of Mexican nationals, remained binding.
"The United States continues to be under an obligation to fully implement it," said the International Court of Justice (ICJ), also known as the World Court.
The proceedings go back to 2003, when Mexico brought a case against the United States, arguing that 51 of its citizens sentenced to die in U.S. jails had not been informed of their right to consular assistance.
This right typically means diplomats can visit and give legal advice to their nationals in detention.
Texas executed one of the Mexicans covered by the original ICJ judgment, 33-year-old Jose Medellin, by lethal injection on August 5. He had been convicted of the 1993 rape and murder of 16-year-old Elizabeth Pena in Houston.
U.S. President George W. Bush had ordered Texas to review Medellin's case but the U.S. Supreme Court ruled that Bush had no authority to do so.
"There are still 42 Mexican nationals who ... still need to get review and reconsideration. We now have the ICJ ruling for us to keep on insisting on the U.S. international obligations," said Joel Antonio Hernandez Garcia, legal adviser of the Ministry of Foreign Affairs of Mexico.
Several other Mexicans have had their cases reviewed.
"This is an opportunity for the Obama administration to show the world that it will respect the rule of law, even when it's politically unpopular at home," David Fathi of Human Rights Watch said.
The United States accepts that the original 2004 ruling places on it a binding legal obligation, said John Bellinger, legal adviser at the U.S. Department of State, adding it was disappointing the court had held that Medellin's execution violated international law.
"Mr. Medellin has had numerous reviews of his case ... It is worth noting that his absence of consular notification was in fact specifically reviewed by a number of state and federal courts," Bellinger said.
Under the Vienna Convention, foreign nationals have a right to talk to consular officers after their arrests.
When Medellin's execution became imminent, Mexico again sought relief from the Hague-based court and won a ruling on provisional measures last year.
But the ICJ has dismissed most of its new legal arguments intended to force the U.S. federal government to act on the issue.
Bellinger said he did not believe that the case and the U.S. withdrawal from an optional protocol to the Vienna Convention would put U.S. citizens abroad at greater risk.
"We remain absolutely committed to providing consular notification inside the United States and we expect that our nationals around the world will be provided consular notification," he said.
(Editing by Andrew Roche)