MANILA, Philippines (AP) -- Pope Francis says he will focus on the poor, the exploited and victims of injustice during his four-day trip to the Philippines.

Pope Francis waves to Filipinos upon his arrival in Manila, Philippines (AP Photo/Aaron Favila)

Francis was greeted by ecstatic crowds when he arrived in Manila on Thursday on the first papal visit to Asia's largest Catholic nation in 20 years. The pontiff described his priorities for the second leg of his Asian trip during his flight to Manila from Sri Lanka.

"The central nut of the message will be the poor, the poor who want to go forward, the poor who suffered from Typhoon Haiyan and are continuing to suffer the consequences," he said.

His message will resonate in a country where poverty afflicts nearly a quarter of the 100 million people, and where many Filipinos leave their families in search of jobs abroad.

Church bells tolled across the country and hundreds of children danced and waved small Philippine and Vatican flags as the pontiff emerged from the plane and was welcomed by well-wishers led by President Benigno Aquino III. A sudden gust of wind blew off his papal cap seconds after he appeared, and Francis grabbed futilely for it and then smiled and descended the stairs from the plane.

Young Filipinos in matching white T-shirts gave him a rousing, thumping hip-hop welcome that drew the flight attendants from the plane out onto the stairwell to watch.

On the tarmac, a boy and a girl from a house for street children handed flowers to the pope, who embraced them.

"I told him bienvenido (welcome in Spanish)," 9-year-old Lanie Ortillo said, adding the pontiff smiled and replied, "Yes, bienvenido."

Francis then boarded his white, open-sided popemobile and his motorcade began rolling along the 11-kilometer (6.8-mile) route to the Apostolic Nunciature in Manila, where he will stay.

Pope Francis is welcomed by two children upon arrival from Sri Lanka at suburban Pasay city south of Manila, Philippines (AP Photo/Osservatore Romano, Pool)

Tens of thousands of people called his name and snapped pictures from behind concrete barriers topped by iron fencing and guarded by policemen along the entire stretch in a trip beamed live on TV nationwide. Francis constantly shifted from left to right, smiling and waving.

The government has declared national holidays during the pope's visit, which runs through Monday. He will be in the capital, Manila, and fly Saturday to eastern Leyte province, where he plans to meet survivors of Typhoon Haiyan that left thousands of people dead in 2013.

Cardinal Luis Antonio Tagle, archbishop of Manila, said he hopes the visit by Francis, the first Latin American head of the 1.2 billion-strong Roman Catholic Church, would be festive and spiritually uplifting and nurture compassion at a time when the country is still recovering from recent deadly disasters, including Haiyan.

"It's like a big, big, big, big national fiesta," a beaming Tagle said in an interview on the eve of the pope's arrival. The visit, he said, "comes at that point when people would really be helped by a moral and spiritual boost coming from someone who really cares."

Francis will meet on Friday with Aquino, who has waged a campaign against poverty, an issue close to the pope's heart, but has clashed with Catholic leaders over a reproductive health bill that promoted use of artificial birth control. Congress, which is dominated by Aquino's allies, passed the bill in 2012.

Meetings with Filipino families, Catholic Church leaders and the youth were also slated.

During his time in Sri Lanka, the pope traveled to the jungles of the war-torn north for a show of solidarity with the victims of the country's 25-year civil war, urging people to forgive one another "for all the evil which this land has known."

"It is very important to keep our country peaceful and have our religious strength become more and more after this visit," said Sumith Periera, an engineer who came to see the pope off.

The pope's trip has given Philippine authorities daunting security challenges, including an outdoor Mass in a historic Manila park on Sunday that officials say could draw a record 6 million people.

About 50,000 policemen and troops have been deployed to secure the pope in a country where relatively small numbers of al-Qaida-inspired militants remain a threat in the south despite more than a decade of U.S.-backed military offensives.

Spanish colonialists introduced Christianity in the 16th century and today just over 80 percent of the Philippines' 100 million people are Catholics, with other Christians making up about 12 percent. Muslims account for 5.6 percent, most of them in the south.

(© 2015 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed)