Mexican President Andres Manuel Lopez Obrador asked Spain on Tuesday to set up a kind of fact-finding commission on the 1519-1521 conquest of Mexico to determine what kind of apology is warranted.

Spanish Foreign Minister Josep Borrell quickly knocked the idea down, saying, "Obviously Spain will not issue these apologies that have been requested."

"It seems a little strange that apologies are being demanded now for things that happened 500 years ago" Borrell said during a trip to Argentina. "In the same sense that we are not going to demand that France apologize for the actions of Napoleon's soldiers when they invaded Spain"

Lopez Obrador's proposal to stir up old ghosts has drawn some puzzled reactions in Mexico as well. Some wondered if Mexico would demand apologies from France or the United States — both of which also invaded Mexico — and some noted Lopez Obrador's grandfather was Spanish.

Lopez Obrador said he wants the commission to determine what abuses were committed, so Spain can apologize. Most of Mexico's indigenous population died within decades after the Spanish arrived, largely by diseases carried from Europe.

"What we want to see is if we can put together a joint group to do some fact-finding about what happened, and humbly, based on that, accept our mistakes," Lopez Obrador said Tuesday. "That way, we will know what happened 500 years ago, how things happened, if there were abuses or not."

Few would seriously doubt there were abuses by Spanish conquistador Hernan Cortes from the time he fought his first battle against Chontal Indians in Tabasco around March 25, 1519, marking the start of what Mexicans call "The Conquest."

But the Spanish government has argued that "the arrival, 500 years ago, of Spaniards to what is today Mexican territory cannot be judged in the light of contemporary considerations."

For about a century, Mexico had been willing to let slide the assessment of historic guilt associated with the Conquest.

The official philosophy was stated on a plaque erected in the 1960s at Mexico City's Tlatelolco Square, commemorating the final battle on August 13, 1521, when the Aztec empire fell to the Spaniards.

"It was neither a triumph or a defeat, it was the painful birth of the mestizo (mixed-race) country that is Mexico," the plaque reads.

Indeed, prior to Lopez Obrador's demand Monday for an apology from Spain, most Mexicans appeared content to let the anniversary pass unheeded.

Rosa Maria Gonzalez Moreno, 61, a primary teacher, had walked by Mexico City's Jesus Nazareno church for years and never knew it held Cortes' tomb.

In fact, the metal plaque marking what is thought to be Cortes' final resting place is barely visible near the altar. It wasn't until a week ago, when Gonzalez Moreno attended the rehearsal for her godson's first communion, that another parishioner told her about the tomb.

"Imagine, I walked by here every day for years and never knew it was where Cortes was buried," said Gonzalez Moreno. "You have to learn about history, the good and the bad. The Spaniards brought bad things, but also good things. Some say without them we never would have had our Catholic religion."

One thing that is being reconsidered is how massive the effects of the Conquest were: One recent study suggests it may have changed the global climate.

The study by researchers at University College London suggested that the deaths of so many indigenous people across the hemisphere may have triggered mass forest grow-backs, sucking so much carbon out of the atmosphere that global temperatures fell in the late 1500s and 1600s.

Now some of the reconsideration has taken unexpected directions.

A senator from Lopez Obrador's leftist Morena party, vegan actress Jesusa Rodriguez, suggested Mexicans should give up their beloved roast pork tacos because the Spaniards brought the first pigs to the Aztec capital, known as Tenochtitlan.

"You should realize that every time you eat roast pork tacos, you are celebrating the fall of Tenochtitlan," Rodriguez said in a video on March 14.

Former president Felipe Calderon called Rodriguez "delirious," and acted as if she had attacked Mexico's national values.

"I love carnitas (roast pork), they are a symbol for us," Calderon wrote.

Lopez Obrador says he doesn't want confrontation and views the 500th anniversary of the conquest as a chance to have a "year of reconciliation." He noted that 2021 would also mark the 200th anniversary of Mexico's Independence from Spain.

Lopez Obrador acknowledged Tuesday that not all the abuses were committed by Spain. He offered to apologize to indigenous groups for abuses committed by Mexico once it threw off Spanish rule.

But the president said he couldn't attend the anniversary of the April 22, 1519, founding of the city of Veracruz, because, until things are cleared up, he's in no mood for celebration.

Historian Rodrigo Martinez Baracs said Mexico has to move beyond a black-and-white vision of the events.

"We Mexicans reject the Conquest, Cortes and the Spaniards so much because of a version of history born during the Independence period, when they created the image of Spaniards as evil, greedy and strong and Indians as weak, innocent and poor," wrote Martinez Baracs. "This Liberal-era history ... stressed a sort of inferiority complex that has to be overcome."