President Barack Obama will today tackle one of the most troubled periods of US history with Argentina, visiting a memorial to victims of the country's murderous US-backed dictatorship.
Obama will visit the Parque de la Memoria near Buenos Aires, a monument to the estimated 30,000 people who were killed or went missing from 1976-1983, and deliver a speech.
Obama's two day visit coincides with the 40th anniversary of a right-wing military coup, which the US government condoned and which ushered in the dictatorship.
During his visit, Obama has tried to present a softer side of the hemisphere's preeminent power.
He joked about tasting Argentina's national beverage mate for the first time and about trying to meet football superstar Lionel Messi, while fondly recalling reading books by Argentine writers Jorge Luis Borges and Julio Cortazar.
He even had a go at tango -- with a pro, at a state dinner, no less.
Looking relaxed while practicing a few steps with dancer Mora Godoy, while his First Lady Michelle Obama gave it a whirl with dancer Jose Lugones, the Obamas held their own on tango's home turf.
But the past has never been far away.
In 2002, Washington declassified 4,000 diplomatic cables which showed US officials, including then-secretary of state Henry Kissinger, encouraged the military junta's purge of leftists.
While acknowledging "moments" in American foreign policy "that were counterproductive" Obama pushed for reconciliation during his first full day in Argentina Wednesday.
In a strategic gesture, Obama agreed to declassify sensitive military and intelligence records linked to the "dirty war."
The intelligence and military documents could shed new light on the depth of US involvement in the coup and in the purges which followed.
"Prior US government releases have detailed human rights abuses and US policymaking in Chile, Guatemala, El Salvador," said Carlos Osorio at the National Security Archive.
They may also shed more light on the extent of US involvement in "Operation Condor," a plan among secret police agencies across the Southern Cone to target communists, leftists and dissidents.
"We all need and we are entitled to know what the truth is," said Argentine President Mauricio Macri, who had asked for the documents to be released.
Obama's visit has angered some victims' groups. Several have called on Obama to apologize for US support of the military regime.
