Updated

The Supreme Court agreed Friday to hear the appeal of a Mexican national on death row in Texas, stepping into an international debate over the legal rights of foreigners in capital punishment cases.

The World Court (search) at The Hague ruled earlier this year that the United States violated the rights of 51 Mexicans on death row, including Jose Medellin, whose appeal will be heard at the Supreme Court next spring.

The world court, which is the United Nations' (search) highest judiciary, had determined that American officials should give the inmates "meaningful review" of the convictions and sentences now, on grounds that the U.S. government failed to inform their home countries of their arrests and trials. The world court is charged with resolving disputes between nations, but cannot force the United States to follow its decisions.

Lower U.S. courts had blocked appeals by Medellin, and justices will decide whether those decisions were wrong.

The announcement broadens the Supreme Court's inquiry into capital punishment this term. Justices are already considering a case that will decide if it's unconstitutional to execute killers who committed their crimes as teenagers.

Medellin was supported in his Supreme Court appeal by dozens of countries, legal groups and human rights organizations, as well as former diplomatic leaders and the European Union.

They argued that U.S. officials have disregarded the 1963 Vienna Convention (search) which requires an "arresting government" to notify a foreign national of the right to talk with the detainee's consulate or embassy, and says foreign governments can arrange legal help for their nationals. It applies to Americans abroad and to foreigners arrested in the United States.

About 6,000 Americans are arrested or detained each year in other countries and need consular help to "navigate and understand an unfamiliar, and perhaps hostile, legal system," justices were told by a coalition of former diplomatic leaders and nonpartisan groups. They said Americans would suffer if the United States does not set a good example.

Texas attorneys had argued that it was too late for Medellin to bring the challenge, because he did not file objections at his trial that the Mexican government was not told of his arrest and allowed to help in his defense.

Mexico's lawyer, Sandra Babcock, told justices in its filing that Medellin's lawyer was suspended from practicing law for ethics violations during the case. Mexico, she said, would have made sure that Medellin had a competent lawyer and money for experts and investigators if it had known about the 1994 trial.

Medellin was one of five gang members sentenced to death for the rape-murders of two teenage girls in Houston -- 14-year-old Jennifer Ertman and 16-year-old Elizabeth Pena.

Last November, the Supreme Court refused to consider the case of another Mexican national, on Oklahoma's death row, who claimed police and other authorities never told him he had the right to meet with Mexican consular officials after his arrest. Justices John Paul Stevens and Stephen Breyer went on record noting misgivings with the decision. Oklahoma's governor commuted Osbaldo Torres' sentence to life in prison without parole following the ruling by the world court.

Medellin is among 118 foreign nationals from 32 countries on death row in America, according to the Death Penalty Information Center. Fifty-three of those people are from Mexico, which does not use the death penalty.

The jurisdictions with foreign nationals on death row, according to the center, are: California (43), Texas (27), Florida (22), Arizona (5), Nevada and Ohio (4 each), Louisiana (3), Pennsylvania and the federal government (2 each), and Georgia, Mississippi, Montana, Oklahoma, Oregon and Virginia (1 each).

The case is Medellin v. Dretke, 04-5928.