Pope John Paul said on Monday religious freedom might be threatened in some European countries that confused the official separation of church and state with a ban on religion in the public sphere.
Addressing the Vatican's diplomatic corps, the pontiff said a recent debate about mentioning the continent's Christian heritage in the European Union's planned constitution showed some states had trouble accepting religion in public life.
He did not explicitly mention another debate about banning Muslim headscarves in public schools in France, Germany and Belgium, but the wording of his speech delivered in French hinted strongly that he also had this in mind.
The ailing 83-year-old head of the Roman Catholic Church, who spoke in a clear voice, devoted much of the speech to denouncing terrorism and welcoming the fact Iraq had been "ridded of an oppressive regime."
"In this recent period, we have been witnesses to an attitude in some European countries that could effectively endanger religious freedom," the pope said.
He said officials often defended a decision to keep religion out of public life by citing the separation of church and state, but this was a wrong understanding of the concept.
"In a pluralist society, secularism means there is a forum for communication between various spiritual traditions and the nation," he said.
France is planning to ban all religious symbols in public schools as a way to bar Muslim schoolgirls from wearing headscarves. All major religions in France have opposed the ban and Muslim leaders say it discriminates against Islam.
Germany and, to a lesser extent, Belgium have also debated banning the veil, which many Europeans see as a sign of growing Islamist influence among their Muslim minorities.
France has western Europe's largest Muslim minority with five million people, or eight percent of its overall population.
"The difficulty to accept religion in the public sphere has been shown by the recent debate about the Christian roots of Europe," the pope added, referring to efforts by traditionally Catholic countries to have the EU constitution mention religion.
EU leaders delayed approving the constitution last month because of a dispute over voting rights, leaving the religion issue unsolved until the text is debated again in coming months.
The pope said some European countries "have read history through reductive ideological glasses, forgetting what Christianity has contributed to the continent's culture and institutions."
Because of its long struggle against the political power of the Catholic Church, France is especially strict in keeping religion out of politics and the public sphere.