Daniel Veselsky, Associated Press
Pope John Paul II blesses a disabled person after a Mass in the St. John the Baptist cathedral in Trnava, western Slovakia.

BRATISLAVA, Slovakia — Pope John Paul II arrived here on Thursday to urge Slovaks not to follow Western Europe's drift from Christianity, but he could not manage to deliver that message in his own trembling voice.

As he made his opening remarks at an airport ceremony, he garbled his words, seemed to lose his place in the text and stopped after a few minutes. An aide took the text and handed it to a Vatican official to read.

The 83-year-old pope then slumped in his chair, looking pale and exhausted, although he had landed in Bratislava after a flight from Rome of less than two hours. He rallied to struggle through the last lines of the speech.

John Paul, 83, suffers from Parkinson's disease, a degenerative neurological disorder, near-crippling arthritis and other ailments. He cannot stand for long without assistance and is wheeled, either in a chair or on a platform, for distances as short as a few yards.

This visit, his third visit to Slovakia as pope, is scheduled to last until Sunday. It is part of his campaign to keep Central and Eastern European countries like his native Poland attached to their Catholic traditions as they look toward a secularized Western Europe.

In May, Slovakia and Poland are scheduled to join the European Union, where the norms are legalized abortion and widespread divorce and where entitlements for gay and lesbian couples are becoming more common. The draft of a first constitution for the union does not mention Christianity's role in European history, despite lobbying by the Vatican. That lobbying continued with a portion of the pope's planned remarks at the airport on Thursday.

"Dearly beloved, bring to the construction of Europe's new identity the contribution of your rich Christian tradition," said that portion, which was read by Msgr. Robert Urland, a Vatican official, in the Slovak language.

The remarks went on to beseech Slovaks to build "a society respectful of human life in all its expressions."

Those words referred to a debate over abortion in Slovakia, whose 5.4 million people are predominantly Roman Catholic.

Abortion is legal in Slovakia for the first 12 weeks of pregnancy. In July, parliament voted to legally validate allowing abortions through 24 weeks of pregnancy if the fetus had a birth defect. Slovakia's president, Rudolf Schuster, vetoed that measure. The pope met with Schuster on Thursday and thanked him.

To underscore their opposition to abortion, Roman Catholic officials here have arranged for the pope to be introduced to a set of conjoined twins during a stop. The point, those officials said, is to showcase people with the kind of abnormalities that, if detected before birth, might lead women to have abortions.