Mexico's presumptive new president Enrique Pena Nieto on Sunday called for a new debate on the war against drugs and urged the United States to take a leading role in reassessing the current strategy.

"We must start a new debate on how we should undertake the war against drug-trafficking," Nieto told U.S. broadcaster CNN.

However, he dismissed a "radical change" in tactics, saying "What we seek now in our new strategy is to adjust what's been done up until now."

The victorious presidential candidate of the once-ruling Institutional Revolutionary Party has hired Colombia's former national police chief Oscar Naranjo as an anti-drug policy advisor.

Since outgoing President Felipe Calderon of the National Action Party launched the war on drugs in 2006, more than 50,000 people have been killed in related violence, but the effort failed to rein in the country's drug cartels.

While decriminalizing drugs has gained ground among some Latin American leaders and intellectuals, Nieto said he does not back the measure.

"Personally, I am not in favor of legalizing drugs. I am not convinced by that argument," he said. "Nevertheless, let's open a new debate, a revision in which the United States plays a fundamental role."

Mexico's Federal Electoral Institute on Sunday released its final results of the July 1 elections, confirming Nieto's win, but supporters of runner-up Andres Manuel Lopez Obrador complained about election-rigging and vowed to challenge the outcome.

The next presidential term begins Dec. 1, 2012 and ends in 2018.