In an interview with The Associated Press on goals for his new administration, Pena Nieto was asked if votes to legalize recreational use of marijuana in Washington and Colorado would make him rethink Mexico's drug-war policy.
"The short answer is no," said Pena Nieto, who said he maintains a personal opposition to legalization. "My government will continue mounting a real fight against the trafficking of marijuana and all other drugs."
He has proposed focusing on reducing violence in Mexico rather than capturing top drug lords, a change from his predecessor, Felipe Calderon. Many have viewed that as a signal that as long as drug gangs don't attack civilians, they would be left alone.
Top Pena Nieto campaign aide Luis Videgaray, now secretary of the treasury, said in November that the U.S. legalization votes would complicate Mexico's anti-drug efforts.
Murder, extortion and kidnapping skyrocketed under Calderon, with some estimates reaching 60,000 drug-related killings during his six-year term.
Legalization "is a theme postulated in the absence of results in the question of public safety," Pena Nieto said. "I will put special attention on prevention, ways we can avoid generating fertile ground that allows violence and insecurity to continue to grow."
The new president, whose inauguration on Dec. 1 brought back Mexico's long-ruling party after a 12-year hiatus, put reforms before Congress even before taking office and has enjoyed a considerable honeymoon in his first week in Mexico's rough-and-tumble halls of congress.
He got leaders of the top two opposing parties to sign his Pact for Mexico, a list of five themes and 95 promises that he has set out to complete during his six-year term.
"That proves there's a great will and commitment, a political disposition on the part of all forces to real push the changes Mexico needs to unleash its potential for growth," he said.
Earlier in the day, Pena Nieto proposed an ambitious reform of the public education system, now run by a closed and autocratic teachers' union and its long-time leader, Elba Esther Gordillo, who controls hiring and paying of teachers. As a result, Mexico doesn't even have an exact count of how many teachers, students or schools the country has.
But Pena Nieto said he would make no promises for his first 100 days in office around achieving education reform, nor the fiscal, social security or energy changes he has proposed as his top priorities.
"I've set my horizon for a year," he said, "...that in a year's time we can achieve agreements and consensus, if not unanimous then at least among the majority for the constitutional and legal changes necessary to put the reforms in place."
The president added that he never set goal of reducing crime by half in the first year, contrary to widely circulated reports.