Pope John Paul II (search) is making a whirlwind visit to Spain this weekend to meet with young people and proclaim five new saints, testing his frail health before a season of ambitious travel plans.

The pope, who turns 83 in three weeks, is resuming travel abroad after a nine-month pause. Though burdened by health problems, he has appeared stronger in recent weeks.

On Wednesday, he greeted pilgrims at his general audience in St. Peter's Square in a loud and clear voice, speaking of the ideal characteristics of a political ruler.

"The ruler's personal life is marked by moral integrity, while his public activity reflects a resolute commitment to combatting every form of injustice in society," John Paul said.

Vatican officials have denied the pope is taking any exotic cure for his ailments -- there have been reports he was taking treatment from papaya extracts -- and attribute any improvements to rest and physical therapy.

The pope suffers from the symptoms of Parkinson's disease (search) -- slurred speech and trembling hands -- as well as hip and knee ailments and uses special lifts and other devices to get around.

His newest equipment is a rolling hydraulic chair that allows him to be raised to the altar so he can remain seated while celebrating Mass.

Vatican officials are optimistic the pope can accomplish his ambitious travel plans, which include a five-day tour of Croatia in June -- trip No. 100 of his papacy -- and a visit to Mongolia in August with speculation he may stop over in Russia.

Church officials in Spain, where the pope has made four previous visits, predict that hundreds of thousands of young people will attend a Saturday rally at an air base outside Madrid (search). John Paul's meetings with youth have been a hallmark of his papacy, now the fourth-longest in the history of the church.

The pope may use the occasion to speak about the aftermath of the war in Iraq, which he opposed. While the Spanish government supported the U.S.-led coalition, surveys showed that a large majority of Spaniards opposed the conflict.

On Sunday, John Paul will preside at a canonization ceremony for a priest killed during the Spanish civil war and four members of religious orders, raising to 469 the number of saints he has proclaimed in his nearly 25-year pontificate. John Paul has stressed the need for models for today's Catholics.

The pope also will meet Spanish political leaders and King Juan Carlos before returning to Rome on Sunday night.