Alberto Fernández has become Argentina's new leader, after being sworn as President of the Nation in front of the Legislative Assembly.
In a ceremony chaired by outgoing Vice-President Gabriela Michetti, Fernández took his oath, pledging fealty to "God and the homeland" before legislators, governors, mayors, judges and international leaders.
The moment was greeted with huge cheers and applause from and outside Congress, with many lawmakers breaking out into song, singing the Peronist March.
Fernández's running-mate, Cristina Fernández de Kirchner, was also sworn in as vice-president, with the former head of state, pledging her loyalty to "God, the homeland and the people, as always."
In a noticeable departure from the enmity that marked the 2015 presidential transition of power, Mauricio Macri was present at Congress to personally hand over the symbolic elements of the presidency – the baton and presidential sash – to the new president personally.
Macri – who becomes the first non-Peronist president to complete his term in 74 years – even extended a handshake to his rival Fernández de Kirchner, who tentatively shook it with a face like thunder.
After embracing his successor, Macri wished Fernández "good luck." He then greet Sergio Massa – but not the new vice-president – before departing the chamber.
Fernández, a 60-year-old lawyer, faces the grave and immediate challenge of trying to pull Argentina from economic crisis: Poverty is above 35 percent, with unemployment and inflation also on the rise, set to close out the year at around 55 percent.
The economy is currently in recession and is expected to shrink three percent by the end of 2019.
Fernández will govern until 2023.
'Call for unity'
"'I come before you to call for unity from all Argentina, to build a new social contract of brotherhood and solidarity," Fernández said in his inaugural address before Congress. "I come before you calling for all to put Argentina on its feet, to put the country on a path toward development and social justice."
He said that his administration's first meeting would focus on reducing hunger, and said that Argentina wanted to pay all its creditors but lacked the capacity to do so.
The new president said on Twitter that he would dedicate himself to "putting my dear Argentina back on its feet."
Fernández served as head of Cristina Fernández de Kirchner's Cabinet for the beginning of her time in power and many wonder if the new vice president will wield outsized power in the new government. Both have denied that.
However, close allies of the former president have already been named to key government positions and her son, Máximo Kirchner, is the head of the governing party in the lower house of the legislature.
Peronists cheered as the pair were inaugurated, saying they had high hopes for an improved quality of life.
"I see a lot of people unemployed, a lot of hunger, and that is very frustrating," said Claudia Pouso, a 57-year-old retiree. I want everything to be turned around, more jobs for people. My daughter works in the hospital and there is nothing there. ... Everything needs to change."
Outgoing Interior Minister Rogelio Frigerio praised Alberto Fernández's conciliatory attitude toward his political opponents, and his openness toward dialogue.
"We have to give the next government the benefit of the doubt, he needs help and we will help," Frigerio said.
The incoming president has already announced plans to fight poverty with the distribution of subsidised basic foods, and he has outlined measures to lower food prices and fight malnutrition in poor families.
He has also announced plans to raise retirees' pensions and increase benefits for public employees and welfare recipients.
Alberto Fernández is expected to move Argentina away from close cooperation with the United States and other conservative governments that are trying to unseat Venezuela's embattled socialist president, Nicolás Maduro.
Fernández is close to former left-leaning Brazilian leader Luiz Inácio Lula da Silva and Mexico's populist president, Andrés Manuel López Obrador. Meanwhile, tensions have been rising between Fernández and far-right President Jair Bolsonaro of Brazil, which Argentina's main trading partner.