WASHINGTON — To put it bluntly, Texas wants President Bush to get out of the way of the state's plan to execute a Mexican for the brutal killing of two teenage girls.

Bush, who presided over 152 executions as governor of Texas, wants to halt the execution of Jose Ernesto Medellin in what has become a confusing test of presidential power that the Supreme Court ultimately will sort out.

The president wants to enforce a decision by the International Court of Justice that found the convictions of Medellin and 50 other Mexican-born prisoners violated their rights to legal help as outlined in the 1963 Vienna Convention.

That is the same court Bush has since said he plans to ignore if it makes similar decisions affecting state criminal laws.

"The president does not agree with the ICJ's interpretation of the Vienna Convention," the administration said in arguments filed with the court. This time, though, the U.S. agreed to abide by the international court's decision because ignoring it would harm American interests abroad, the government said.

Texas argues strenuously that neither the international court nor Bush, his Texas ties notwithstanding, has any say in Medellin's case.

Ted Cruz, the Texas solicitor general, said the administration's position would "allow the president to set aside any state law the president believes is inconvenient to international comity."

The Supreme Court will hear arguments in the case Wednesday.

Medellin was born in Mexico but spent much of his childhood in the United States. He was 18 in June 1993, when he and other members of the Black and Whites gang in Houston encountered Jennifer Ertman and Elizabeth Pena on a railroad trestle as the girls were taking a shortcut home.

Ertman, 14, and Pena, 16, were gang-raped and strangled. Their bodies were found four days later.

Medellin was arrested a few days after the killings. He was told he had a right to remain silent and have a lawyer present, but the police did not tell him that he could request assistance from the Mexican consulate under the 1963 treaty.

Medellin gave a written confession. He was convicted of murder in the course of a sexual assault, a capital offense in Texas. A judge sentenced him to death in October 1994.

Four of Medellin's fellow gang members also received the death penalty and one, Sean O'Brien, was executed last year. Two others had their death sentences commuted to life in prison in 2005 when the Supreme Court barred executions for those who were age 17 at the time of their crimes. Another defendant does not have an execution date.