BUENOS AIRES (AFP) - Fresh from his landmark trip to Cuba, US President Barack Obama travelled on Wednesday on to Argentina, where resentment still simmers four decades later over Washington's backing for its former dictatorship.
After calling for freedom and democracy as he stood alongside Cuba's communist leaders on the first leg of his regional visit, Obama touched down in another Latin American nation with a history of delicate relations with the United States.
Obama, who hopes to remake the United States' image in Latin America, met Argentina's new free market-friendly President Mauricio Macri at the Casa Rosada presidential palace in Buenos Aires on Wednesday morning.
Roads were closed as Obama's motorcade headed to the Casa Rosada, where he and Macri were scheduled to give a news conference shortly before 1600 GMT (midnight Singapore time).
Tuesday's deadly bomb blasts in Brussels prompted Argentina to put its security forces on high alert as it received Obama, who is travelling with First Lady Michelle Obama, their two daughters and his mother-in-law.
There was a security alert when police arrested a man who burst into the offices of a state radio station near the presidential palace threatening to blow the building up, station employees told media.
The building was evacuated and no one was reported hurt.
It is the first visit by a US president to Argentina since 2005. That year George W. Bush was met by angry protests at a summit where regional leaders blocked his plans for a free-trade deal.
Macri has reached out to Washington and other foreign powers since taking office in December after years of combative relations under his leftist predecessors.
But the delicate issue of US involvement in Latin America's violent history will rear its head during Obama's visit to Buenos Aires - after the Havana visit touched on sensitivities over human rights in Cuba.
On Thursday morning, Obama will pay homage to victims of the "dirty war" by Argentina's dictators against dissidents.
That day marks the 40th anniversary of the military coup that started the 1976-1983 dictatorship. Declassified documents have shown that top US officials backed the coup and America's wider image in Latin America was tarnished by involvement in coups and death squads.
After the talks with Macri, Obama was due to lay a wreath at Buenos Aires Metropolitan Cathedral and meet local people, before attending a state dinner.
His administration said last week it would declassify military and intelligence records linked to Argentina's "dirty war."
"We're determined to do our part as Argentina continues to heal and move forward as one nation," said Obama's National Security Advisor Susan Rice.
The sensitive date of the Argentina visit angered some victims' groups. Several organisations have called on Obama to apologise for US support of the military regime.
But four opinion polls showed a majority of Argentines approved of Obama's visit.
Obama "believes that part of moving forward in the Americas or any other part of the world involves a clear-eyed recognition of the past," said Ben Rhodes, one of the president's top advisors.
"He will be more than willing to speak to what took place 40 years ago, to the suffering that took place after the coup and to the complicated history between the United States and Argentina as it relates to those events."
Adolfo Perez Esquivel, 84, an Argentine human rights activist who like Obama is a Nobel Peace Prize laureate, recalled that US military academies trained troops from Argentina and other Latin American regimes in torture techniques.
"It would be good to have a public recognition of United States interventionism," he said.
Some small leftist groups called for demonstrations against Obama's visit in Buenos Aires and in the Andean resort town of Bariloche, where the Obamas are due to head on Thursday for a few hours' leisure time.
Demonstrations are also planned Thursday in memory of the dictatorship. Some vowed also to protest in anger at the treatment of Argentina by its US creditors.
Macri's government has reached a settlement with US hedge funds that his predecessor Cristina Kirchner branded "vultures."
The Obamas are scheduled to leave Argentina on Thursday night.