Bratislava, Slovakia ? Slumped in his chair and slurring his words, Pope John Paul II struggled Thursday at the start of a trip to press Roman Catholic values on skeptical Europeans.

The frail 83-year-old pope, who is battling Parkinson’s disease and crippling knee and hip ailments, looked pale and short of breath as he failed to read his full arrival speech for the first time in 102 foreign trips. An aide read most of the rest.

Later, visiting a cathedral in the western city of Trnava, John Paul thanked the crowd in Polish for its warm welcome, but left it to Slovak Cardinal Jozef Tomko to read his brief prayer service remarks.

Just before the service, Vatican officials wheeled the pope into the sacristy and two aides brought in what appeared to be medical equipment. John Paul emerged 10 minutes later. No explanation was given.

Papal spokesman Joaquin Navarro-Valls dismissed the idea of any medical emergency, saying if medical equipment was moved around the church, it was not for the pope.

On other foreign visits, aides have read parts of the pope’s speeches but never his arrival texts. His feeble appearance Thursday will raise questions about the ability of history’s most-traveled pope to keep on the road.

Pope John Paul II rests during a ceremony Thursday at a cathedral in Trnava, Slovakia.

Navarro-Valls said the pontiff would “absolutely” finish his third visit to Slovakia, a grueling four-day pilgrimage that will take him to four cities in this predominantly Catholic nation that suffered during decades of communist rule.

Although this is John Paul’s last scheduled trip this year, Vatican planners are considering invitations from Switzerland, Austria and the pope’s native Poland for next year.

“I don’t see any real obstacle” to future travel, Navarro-Valls said. Relying on others to help the pope read, he said, “is logical to ease his burdens.”

As he has in recent appearances, John Paul remained seated in a thronelike chair wheeled by aides. It took him 20 minutes to disembark from the papal plane on a hydraulic lift.

Reaching out to Slovakia, which joins the European Union next year, the pope touched on what has become a recurrent theme: a plea to Europeans to resist materialism and reaffirm traditional family values in the face of liberal abortion laws and growing legal recognition of homosexual unions.