Pope Francis on Friday demanded leaders in the Philippines end "scandalous social inequalities", hitting out at corruption in a nation where tens of millions of Catholics endure brutal poverty.
The pontiff made the comments in his first speech of a five-day visit to the Philippines, after an electrifying welcome on Thursday enhanced the nation's reputation as the Catholic Church's vibrant Asian bastion.
Francis, a revered figure for most Filipinos, took immediate aim at the nation's elite who have for decades enjoyed the spoils of power while the vast majority lived in poverty.
"It is now, more than ever, necessary that political leaders be outstanding for honesty, integrity and commitment to the common good," the pope said in the speech at the presidential palace.
He challenged "everyone, at all levels of society, to reject every form of corruption, which diverts resources from the poor".
The 78-year-old pontiff, seen by many around the world as a bold reformer compared with his predecessor, said the "great biblical tradition" obligated everyone to hear the voice of the poor.
"It bids us break the bonds of injustice and oppression which give rise to glaring, and indeed scandalous, social inequalities," he said.
Francis had moments earlier met President Benigno Aquino, who has waged a high-profile campaign against corruption since coming to power in 2010 that has seen his predecessor and three senators detained.
Aquino also orchestrated the impeachment of the Supreme Court's chief justice on corruption charges, and he has won international plaudits for his efforts.
But critics of Aquino, the son of democracy heroine Corazon Aquino, have accused him of focusing his anti-graft campaign only on opponents and not allies.
They also point out his family has for decades been one of the elite.
And, despite Aquino presiding over some of Asia's strongest economic growth, his time in office has failed to make a major dent on poverty.
About 25 million Filipinos, or one-quarter of the population, live on the equivalent of 60 cents a day or less, according to the latest official poverty surveys.
The poverty has forced more than 10 million Filipinos to head overseas in search of a better life.
Francis said one of the main purposes of his trip was to visit survivors of Super Typhoon Haiyan, known in the Philippines as Yolanda, which left 7,350 people dead or missing in 2013.
He will spend Saturday in areas of the central Philippines that were devastated by the typhoon, which smashed into coastal communities with the strongest winds ever recorded on land.
"In a particular way, this visit is meant to express my closeness to our brothers and sisters who endured the suffering, loss and devastation caused by Typhoon Yolanda," he said.
While in Tacloban, the pope is expected to get some first-hand experience of the tropical storms and typhoons that claim hundreds of lives each year in the Philippines.
A tropical storm in the area will bring "heavy to intense" rain on Saturday, according to the Philippine weather agency.
The Philippines has long been the Church's stronghold in the region, with Catholics accounting for 80 percent of the former Spanish colony's population.
Francis enjoyed a hero's welcome when he arrived on Thursday night, with hundreds of thousands of people crowding the streets of Manila to get a first glimpse of him as he travelled in a motorcade.
Massive crowds continued to choke his motorcade route on Friday as he travelled around the city, including near the centuries-old Manila Cathedral where he celebrated mass with priests and nuns.
"My sacrifice was worth it. I feel happy. I feel blessed," Nanette Hermano, 56, told AFP as she cried after taking a smartphone picture of the pope outside the cathedral.
"I've been here since 3:00 am, but I don't feel tired, I don't feel hungry. It's like a miracle."
Later in the day Francis will lead thousands of people in prayer at Manila's top concert arena, where music fans have flocked in recent years to see the likes of Bruno Mars, Lady Gaga and Taylor Swift.
Pope-mania will reach a peak on Sunday, with organisers expecting him to attract as many as six million people for mass at a Manila park.
If as big as expected, the crowd will surpass the previous record for a papal gathering of five million during a mass by John Paul II at the same venue in 1995.
Francis is on a week-long tour of Asia that began in Sri Lanka.
It is his second trip to the region in five months, signalling the importance the Vatican places on Asia's growth potential for the Church.