WASHINGTON – A last-minute decision by President Bush in February to comply with a decision of the International Court of Justice may save his administration from a broader ruling by the U.S. Supreme Court on whether America must follow the world court’s opinions.

The international court ruled last year that American authorities violated the rights of 51 Mexican nationals on death row when they neglected to advise the Mexicans of their right to assistance from the Mexican consulate at the time of their arrest. The court said the American courts should review the convictions.

The 1963 Vienna Convention on Consular Relations, ratified by America in 1969, requires such notification. America also signed a provision that allows any disputes arising from the treaty to be decided by the international court at The Hague.

Lower courts have declined to follow the international court’s ruling and review the convictions, and the Bush administration has argued the court’s decisions are not binding on U.S. courts.

However, last month the president issued a directive that state courts should review the cases of the Mexicans for diplomatic reasons.

The Supreme Court had agreed to wade into the closely watched issues of international law in the case of one of the death row inmates, Jose Ernesto Medellin. But at an oral hearing yesterday, the justices expressed reluctance to enter into the case in the wake of Mr. Bush’s directive.

“Is it not entirely possible that the Texas decisions would make this proceeding entirely moot?” asked Justice Stevens at one point. The federal litigation may amount to “a lot of useless activity,” he said.

Medellin is challenging his 1994 conviction and death sentence for his role in the gang rape and murder of two teenage girls in Texas. Texas courts declined to reconsider his case because the treaty issues had not been raised at trial.

While Medellin’s lawyer, Donald Donovan, argued that the president’s move merely confirmed that the international court’s decisions should be followed, the justices appeared unwilling to make any sweeping statement about the weight of the court’s decisions in America.

Rather, they debated whether the case should be stayed pending the proceedings in Texas or dismissed altogether given the recent developments.

A lawyer for Texas, R. Ted Cruz, told the justices that they “need not and should not address the many interesting issues of international law that swirl around this case.”

Mr. Donovan asked the justices to merely stay the proceedings until the Texas courts issue the ruling. But Justice O’Connor told him that the court was more likely to dismiss the case.

The deputy federal solicitor general, Michael Dreeben, told the justices that if they ruled that the international court’s decisions are binding, they would impose “extraordinarily broad consequences” on the president’s freedom to pursue diplomacy in cases where the rulings of the court conflict with the administration’s foreign policy.

Medellin’s position was backed by numerous European and Latin American countries, an array of human rights groups, former diplomats, professors of international law, and legal groups including the Association of the Bar of the City of New York.

Texas was backed by other professors and legal groups, as well as Senator Cornyn, a Republican of Texas, who argued in a written brief that subjecting American courts to judgments of the international body would violate American sovereignty.

Although it appeared unlikely that the court would rule on the international law issue, several justices probed the relationship between international treaties and domestic law.

“Is a treaty that has been ratified and signed, enforceable as part of our law?” asked Justice O’Connor.

“Yes,” replied Mr. Dreeben. “But [it is] not to be interpreted as conferring individual rights in criminal cases.” The treaty can be enforced only by the political branches of government, he argued.

Justice Scalia was openly hostile to the notion that the decisions of the international court should bind American judges. “What if I think that all questions of federal law … are to be decided only by the Supreme Court?” Justice Scalia asked Mr. Donovan.

In an effort to avoid such conflicts in the future, the Bush administration has notified the United Nations that it is pulling out of the section of the treaty that gave the international court jurisdiction over disputes.