Pope Francis has called on leaders to fight corruption and end "scandalous" social inequalities, on the first full day of his visit to the Philippines.
The Pope was speaking at a welcome ceremony at the presidential palace hosted by President Benigno Aquino.
He then went on to celebrate Mass in the capital's Basilica of the Immaculate Conception.
The pontiff was greeted by huge crowds as he arrived in the overwhelmingly Catholic country on Thursday.
The highlight of the papal visit will be on Sunday, when an open-air Mass is expected to attract millions. He will also travel to the typhoon-hit city of Tacloban on Saturday.
The Pope is on a six-day tour of Asia. Earlier in the week he visited Sri Lanka.
'Voice of the poor'
The Pope received a rapturous reception as he arrived in Manila Speaking at Friday's welcome ceremony to the Philippine president and other officials, Pope Francis called for leaders "to reject every form of corruption, which diverts resources from the poor" and to make concerted efforts to ensure inclusivity.
"It is now, more than ever, necessary that political leaders be outstanding for honesty, integrity and commitment to the common good," he added.
He said it was a Christian duty to "break the bonds of injustice and oppression which give rise to glaring, and indeed scandalous, social inequalities".
Corruption has been a longstanding issue in the Philippines. It placed 85 in Transparency International's latest Corruption Perceptions Index.
Later as he celebrated Mass, the pontiff also called on the Church in the Philippines "to acknowledge and combat the causes of the deeply rooted inequality and injustice which mar the face of Filipino society".
Ahead of his arrival, he had said that the poor were the focus of his visit, including people hit by the deadly Typhoon Haiyan in November 2013.
On Saturday will meet survivors of the storm, which left more than 7,000 people dead or missing, in Tacloban, the worst-affected area.
He has paid tribute to the "heroic strength, faith and resilience" shown by Filipinos in dealing with the typhoon's aftermath, says the BBC's religious affairs correspondent Caroline Wyatt who is in Manila.
Our correspondent says there is an atmosphere of celebration on the streets of Manila. Roads in the city centre have been shut off, and big screens erected to screen the Mass at the Cathedral.
National holidays have been declared in the capital for the duration of the Pope's visit.
Security is very tight, with tens of thousands of soldiers and police deployed, after failed attempts to kill two previous popes in the Philippines.
Source - BBC