Mexico City - Mexican President Enrique Peña Nieto approved a law in June calling on the Health Ministry to write rules for the medical use of marijuana.

Initially, many politicians, including Jose Luis Oliveros Usabiaga, a member of the center-right National Action Party and youth committee chair in the lower chamber of Congress, opposed the legislation when it was being debated.

"My opposition, of course, was to addiction. It felt like giving a child a gun to play with," Oliveros Usabiaga said.

But the country's Supreme Court later determined that the prohibition of the consumption or cultivation of marijuana violated fundamental human rights. Oliveros Usabiaga, who has since stepped down from office, now supports legalization, he said.

Peña Nieto eventually gave a speech at the United Nations lamenting the human toll of the country's decade-long drug war against drug traffickers and pledging to push for legislation allowing the medical use and scientific research of marijuana.

"Thousands of lives depend on this," Peña Nieto said.

So does this mean Mexico will suddenly legalize marijuana for recreational or medical use?

"No, no, no. We're still far from that," said Alejandro Madrazo, a law professor and head of the drug policy institute at Mexico's Center for Research and Teaching in Economics.

Given the Mexican government's no-to-drugs, tough-on-crime history, Madrazo expects the Health Ministry to issue very conservative rules, he said. This potentially means only the use of hemp oil.

But, Madrazo adds, the new law opens the door for future administrations to write more broadly applicable rules for the medical use of marijuana or for recreational use. It also means Mexican pharmaceutical companies could be allowed to apply for marijuana patents that would have to be respected in the more than 40 countries where Mexico has trade treaties, Madrazo said.

"The patents made here would immediately have to be respected elsewhere in the world as marijuana becomes legal for medical use," Madrazo said.

The Health Ministry has until the end of the year to issue its rules.