Hundreds of thousands of people gathered in the Ecuadorean port city of Guayaquil on Monday to greet Pope Francis.
The Pope waved to the crowds from his custom car ahead of an open-air mass in the city's Samanes Park.
He arrived in Ecuador on Sunday for the first leg of his three-country trip to Latin America, which will also take him to Bolivia and Paraguay.
It is his second visit to the region since becoming pontiff in 2013.
City officials said a million visitors had travelled to Guayaquil to see the Pope.
Looking relaxed, Pope Francis smiled as the crowds in Guayaquil cheered him and snapped selfies.
Before his procession he visited the city's Divine Mercy shrine, where he reacted with good humour to nearly being poked in the eye by a young boy.
He spent a minute praying at the shrine and told the crowd he would pray for them.
A Vatican official estimated that half a million people had lined the streets of the Ecuadorean capital, Quito, on Sunday, to see the Pope.
Many also gathered in front of the Vatican Embassy in Quito, where he stayed the night.
He joined them for a prayer and, according to some of those present, said: "I am going to give you a blessing so that you go home and rest and let the neighbours get some sleep."
After landing in Quito, the Pope thanked God "for having allowed me to return to Latin America".
His 2013 visit to Brazil drew huge crowds of young Catholics attending the Catholic Youth Conference. A Mass on Copacabana beach was estimated to have been attended by three million people.
But this time the Pope chose some of the smaller and poorer countries of the region for his visit, a move which the Vatican said reflected his interest in the "peripheries".
Pope Francis is the first leader of the Roman Catholic Church to come from South America, but on this occasion he will not be visiting his home country of Argentina.
The Vatican said that he would focus on the issue of poverty and inequality.
"Progress and development must ensure a better future for all," he said in a speech on the Quito airport runway after he was welcomed by Ecuadorean President Rafael Correa.
In 2007, before becoming Pope, he told a gathering of Latin American bishops that they were living in the most unequal part of the world.
On Wednesday Pope Francis will travel to Bolivia.
He has requested to chew coca leaves while in Bolivia, according to Culture Minister Marko Machicao.
Coca, the raw ingredient for cocaine, has been used in the Andes for thousands of years to combat altitude sickness and as a mild stimulant.
In September the Pope will travel to Cuba ahead of a trip to the US.
The pontiff is credited with helping to bring about last December's diplomatic thaw between the two countries.