The United States must do everything possible to prevent Texas from executing five Mexican nationals on death row in the state while their cases are being considered by the International Court of Justice (ICJ), judges in the Netherlands-based tribunal ruled Wednesday.

Mexico contends that dozens of its citizens facing execution in U.S. jails have been denied their right to consular access after their arrests on capital crimes charges.

A series of ICJ rulings have gone in Mexico’s favour since 2004, when the court ordered the U.S. to review the cases of 51 Mexicans facing the death penalty in U.S. jails.

President George W. Bush complied with that order and asked Texas to postpone executions of Mexican convicts, but Texas got a U.S. Supreme Court ruling the following year that said Bush had overstepped his authority.

The state pressed ahead with plans to execute Jose Medellin and has set Aug. 5 as the date he will die by lethal injection.

Medellin was convicted of the rape and murder of two teenage girls in 1993. His lawyers say he was denied his right to see Mexican Embassy officials during his incarceration, but prosecutors said he didn't ask for that right until he had been sentenced to death.

Four other Mexican citizens face imminent execution in Texas.

ICJ has no jurisdiction, U.S. argues

Wednesday’s ICJ ruling says Bush and the U.S. government must try to stop the state from carrying out those death sentences.

"The court indicates that the United States of America shall take all measures necessary to ensure that five Mexican nationals are not executed, pending its final judgment," Judge Rosalyn Higgins said.

The ICJ exists to settle disputes between UN member states, and though its rulings are seen as binding, there is no enforcement mechanism.

U.S. State Department lawyer John Bellinger argued that the ICJ did not have jurisdiction because Bush agreed with Mexico and there was no dispute.

"It almost never happens that the federal government enters [into] state court proceedings," he said, calling the Bush's intervention "highly unusual."

Mexico's chief advocate, Juan Manuel Gomez-Robledo, told the court the U.S. was nonetheless "in breach of its international obligations." He said international law applies not only to nations, but to their component states. He asked the court to clarify its earlier ruling and in the meantime intercede with U.S. authorities to halt the schedule of executions.

Mexico abolished capital punishment in 2005 and objects in principle to the U.S. and other countries sentencing its citizens to die.

The ICJ acknowledged that the U.S. federal government "has been taking many diverse and insistent measures" to persuade Texas not to carry out executions of any of the Mexicans covered by the original 2004 ruling.

Bellinger said that the international court has limited powers over U.S. states or federal authorities in Washington.

"It does not have technical legal effect in the United States that would … have a direct impact either on the United States or on Texas itself," he said.

Federal authorities were still discussing the case "constructively" with Texas, Bellinger said, and "Texas does take this all very seriously."

Mexico's ambassador to the Netherlands, Jorge Lomonaco Tonda, said he was satisfied with Wednesday’s ruling and didn’t expect any executions to take place before a final court decision.

There has been no comment from the Texas authorities on the court order.