Sky News reports the leftist politician, known as Lula, had held Brazil's highest office between 2003 and 2010 after three attempts to get the top job.

Now aged 77, he entered office having defeated far-right candidate Jair Bolsonaro in October with tight security surrounding the Brasilia inauguration ceremony amid fears Bolsonaro supporters may try to disrupt proceedings.

Up to 300,000 people gathered along the esplanade to celebrate following a ceremony in Brazil's congress.

His speech to congress on Sunday outlined many of the issues and political priorities ahead of the leader: investing in education and health.

"The great edifice of rights, sovereignty and development that this nation built has been systematically demolished in recent years. And to re-erect this edifice, we are going to direct all our efforts," he said.

The new president continued his speech by labelling his predecessor's administration as having committed genocide by failing to manage the COVID-19 pandemic which claimed the lives of more than 680,000 Brazilians.

He said he was receiving a ruined country where hunger had returned with depleted resources for some of the areas he wishes to improve, including education, health and the conservation of rain forests.

The economic conditions since Lula was last in power are drastically different, as the commodity boom that funded education and infrastructure projects has come to an end. Now he's faced with paying for COVID-19 costs and globally rising prices.

There had also been concern over Mr Bolsonaro's willingness to accept the results of the tightest presidential race in more than 30 years as political opponents resisted his taking office. Mr Bolsanaro has still not recognised Lula's win and did not attend the event, having left Brazil for Florida on Friday.

A polarized Brazil

The vote was won by less than two percentage points and Mr Bolsonaro spent months sowing doubt about the reliability of Brazil's electronic voting system. For many days after the election was called for Lula, Mr Bolsanaro remained silent and tension mounted as some backers of the former president blocked roads in protest to Lula's victory. Lula takes the reins of a polarized Brazil.

But it wasn't always. When he retired in 2011 it was with 83% approval ratings. A series of scandals led to his imprisonment on corruption charges which were subsequently annulled.

Sky News