THE United States violated international law by executing a Mexican national who was denied his consular rights, UN human rights chief Navi Pillay says.

Texas carried out the controversial execution of Leal Garcia yesterday, despite calls for reprieve from both the White House and Mexican government.

“The execution of Mr Leal Garcia places the US in breach of international law. What the State of Texas has done in this case is imputable in law to the US and engages the United States’ international responsibility,” she said today.

At least 51 Mexicans on death row in the US, including Garcia, were not informed after their arrests that they could get legal help from the Mexican consulate, a violation of the Vienna Convention.

“The lack of consular assistance raises concerns about whether or not his right to a fair trial, guaranteed in the International Covenant on Civil and Political Rights and binding on the United States, was fully upheld,” a statement from Ms Pillay’s office said.

Garcia, 38, was executed at 6.21pm local time Thursday in a Huntsville, Texas prison for the 1994 rape and murder of a 16-year-old girl, state officials said.

The International Court of Justice ruled in 2004 the United States had to review the cases of the 51 Mexican nationals on death row because none had received consular services.

This review never took place, the UN statement said.

The execution, “will undermine the role of the International Court of Justice, and its ramifications are likely to spread far beyond Texas”, Ms Pillay said.

“The federal Congress must also assume its responsibilities and act to remedy the gap in US law that this case has again sadly revealed in order to prevent its recurrence in the future,” Ms Pillay said.

After all, she noted, it is “the responsibility of all federal countries to ensure that all individual states respect the international obligations assumed by the country as a whole”.

In a rare intervention, the US government’s top lawyer had urged the Supreme Court to spare Garcia’s life, saying his execution would cause “irreparable harm” to US interests.

But the Supreme Court denied the request for a stay of execution in a 5-4 decision just over an hour before Leal was set to be put to death.

US State Department spokeswoman Victoria Nuland said Secretary of State Hillary Clinton was “disappointed” that Texas went ahead with the execution.

“US compliance with Vienna convention terms is absolutely critical to ensuring our own consular access and our own ability to protect Americans detained abroad,” she said.