Wiping away a tear as he ended an emotional visit to his native Poland, a frail Pope John Paul II asked his countrymen Monday for their prayers so he can return again before he dies.

"I'm sorry to be leaving," the pope told 30,000 people who saw him off at the airport before he left for Rome. Their response: "Stay with us."

John Paul appeared invigorated by the joyous reception he received during the four-day nostalgic journey tracing his life in Poland.

"Many have waited for my coming. Many have wished to meet me, although not all were able to do so," the pope said in his farewell address. "Maybe next time ..."

"We invite you," the crowd chanted in reply.

The question of whether this would be the pope's final trip to his beloved homeland cast an emotional charge over the visit, the pope's ninth.

Though beset by symptoms of Parkinson's and ailments in his knees and hips that leave him stooped and limited his itinerary to the Krakow region, aides noted the joy the visit brought the 82-year-old pontiff.

"In my personal opinion, the pope will return to Poland," Vatican spokesman Joaquin Navarro-Valls said Monday. "He's in a place that is very dear to him. He has personal links to this place, and his prayer here is very personal and very intense."

Despite his frailties, the pope brushed aside any notion he might step down while in Poland. Underlining his commitment to carry out his papacy, he prayed for strength to continue his mission during a Mass on Monday at a mountain sanctuary where he used to pray with his father.

"Obtain also for me strength in body and spirit that I may carry out to the end the mission given to me by the risen Lord," the pope said.

He also renewed a request for prayers "when I am alive and after I die," referring for the second time during the trip to his own mortality.

Although the pope during his Polish stay made no direct mention of the sex abuse scandal rocking his worldwide church, he offered a prayer for the protection of children "lest they be scandalized."

The trip down memory lane highlighted the bond between the first Polish pope and his countrymen, who thronged him at every stop and cajoled him to remain in Poland.

"With pride and joy we saw how good the pope feels with us," President Aleksander Kwasniewski said at the airport Monday. "We often saw a smile and real emotion on your holiness's face. So I think today we have the right to say good-bye in the conviction that although we tired you out, we nevertheless gladdened our pope."

Typifying the excitement surrounding the pope's visit, bells tolled as the popemobile approached the Kalwaria Zebrzydowska monastery, draped in Polish and Vatican flags. A waiting crowd of some 60,000 people chanted "Your people welcome you, John Paul II."

Kalwaria was the last official stop on the papal itinerary, which included a Mass for an unprecedented 2 million Polish faithful, a return to a sanctuary where he prayed under Nazi occupation and prayers in the cathedral where he said his first Mass as a priest.

There were also quieter moments.

John Paul had a joyful meeting Sunday night, broadcast on Polish television, with a dozen friends from his school days. The pope beamed as the sister of a close friend approached him, and they embraced for a long moment.

Though limited by time and frailty, the pope did not miss a chance to cast his eyes once more on his native Wadowice, flying in a helicopter three times over the main square on the way to Krakow's Balice airport. Below, 12,000 people waving yellow Vatican flags saluted the holy father.

In one last detour after his departure for the Vatican, the pope's Boeing 737 circled low over Krakow, dipped its wings over Wadowice in final farewell, and flew over John Paul's favorites ski resort in the Tatra Mountains -- before returning to Rome.

In parting remarks at the airport, the pope encouraged Poles on the difficult path of economic reform, acknowledging "the cost of the changes that weigh upon the neediest and the weakest, on the unemployed, the homeless."

In language added to the farewell address after meeting Polish leaders in Krakow, he reiterated his support for Poland's ambition to join the European Union -- but urged the nation not to abandon its Christian values in the effort.

"I do hope that by cherishing those values the Polish nation, which has belonged to Europe for centuries, will find its due place in the structures of the European Union," John Paul said.

Poles consider the pope a moral compass who guided them out of communism, and the message reaches them at time of growing dissatisfaction with the price of economic reforms necessary to join the European Union.

"I feel so moved by the holy father, his presence here," said Marcin Madej, a carpenter in Kalwaria. "His words are simple and they can reach everyone."