Arturo Sarukhan, the ambassador of Mexico, said in a letter to Clinton that while Mexico "never called into questions the heinous nature" of the crimes attributed to Leal, it believes that the United States is beholden to abide by the rules of the International Court of Justice (ICJ), which requires consular notification rights.
Sarukhan cited the 2008 execution of another Mexican National, Jose Ernesto Medellin, which he said "was in direct breach" of the United State's international legal obligations.
Clinton and Holder make clear that Leahy's proposed legislation will help protect U.S citizens overseas if they should need access to the U.S. consulates abroad.
"The United States is best positioned to demand that foreign governments respect consular rights with respect to U.S. citizens abroad when we comply with these same obligations for foreign nationals in the United States," Clinton and Holder write.
Asked about the matter at a State Department briefing on Tuesday, spokeswoman Victoria Nuland said, "The concern is that if we don't set a good example here and allow foreign governments to visit their citizens who are detained or arrested, we could face reciprocal denial of access for our consular officials when American citizens find themselves arrested or detained overseas."
Jeffrey F. Pryce, an international lawyer at Steptoe & Johnson, said the legislation is necessary.
"This is a treaty that the United States signed up to, believes it is bound by and wants to comply with," Pryce said. "What's important is that the government has the legal tools to comply with its treaty obligations."
A group of former U.S. diplomats and State Department officials wrote Perry a letter urging him to grant a reprieve for Leal pending congressional action. In the letter the officials bring up the detention of three Americans crossing into Iran in 2009 and highlight U.S. requests at that time asking the Iranian government to "live up" to its obligations to grant consular access to the three individuals.
Pryce says the example is indicative how the fate of one death row inmate in Texas can have international implications. He says, "It's very important when the United States signs a treaty for it to comply with its obligations."
But Cesinger insisted that Congress has been slow to act and without such action Texas is not bound by the ruling of an international court.
"Congress has had the opportunity to consider and pass legislation for the federal courts review of such cases sincee 2008 and has not done so," Cesinger.