"How I would wish that we Christians could be as close to the sick as Jesus was, embracing them and willingly seeking them out," Pope Francis said. "Sadly, our society is tainted by the culture of waste, which is the opposite of the culture of acceptance. And the victims of the culture of waste are those who are weakest and most frail; and this is indeed cruel."

The brief ceremony in the hospital reception area, before a statue of St. John Paul II lifting a child, took place before 50 children in wheelchairs, some hairless from cancer treatment, clasping rosaries and papal flags. Addressing patients, parents and staff, Pope Francis said he was grateful for the sign of love offered by those welcoming and caring for "the smallest and most needy."

He told those gathered: "To serve with love and tenderness persons who need our help makes all of us grow in humanity. ... Those who engage in works of mercy have no fear of death."

Looking solemn after his address, the pope recited the Hail Mary and delivered a blessing, before greeting the young patients and their parents, with the sound of crying children in the background.

Pope Francis said he wished to "draw near to all children who are sick, to stand at their bedside and embrace them," adding that Jesus was "always attentive" and "moved by compassion" toward the sick, regarding them "in the same way that a mother looks at her sick child."

However, he added that families sometimes felt "alone in providing care," and said he wished to "listen to everyone here, even if for only a moment, and be still before questions that have no easy answers."

"From this place, so full of concrete signs of love, I would like to say: Let us multiply the works of the culture of acceptance, works inspired by Christian love," Pope Francis said.

"I encourage all those who have made the Gospel call to visit the sick a personal life decision: physicians, nurses, health care workers, chaplains and volunteers. May the Lord help you to do your work well, here as in every hospital in the world."

He later visited the emergency unit and prayed in the chapel, accompanied by Father Lucjan Szczepaniak, one of 500 Catholic chaplains ministering full-time at Poland's 550 state hospitals.

Dr. Maciej Kowalczyk, hospital director, said the children's hospital represented the last chance for many severely sick children. He said he hoped the pope's words and prayers would give patients and their parents "strength and hope to overcome their illnesses."

Children's University Hospital admits around 36,000 seriously ill young patients per year and treats 180,000 outpatients. It was founded in 1965 with finding from the U.S. government and Poles abroad.