A top Vatican official said Friday that Roman Catholic politicians who support abortion should be denied communion, as church officials in the United States debate how to respond to Democratic presidential candidate John F. Kerry's position in favor of abortion rights.

The official, Cardinal Francis Arinze, declined at a Vatican news conference to say whether the Massachusetts senator should be denied the sacrament. Instead, he spoke generally about Catholic politicians who do not uphold church teachings in their public lives.

Arinze, a Nigerian who is often cited as a possible successor to Pope John Paul II, took questions during the introduction of Vatican rules governing the celebration of Mass. Pressed by reporters to say whether a politician who is "unambiguously pro-abortion" should receive the Eucharist, he said, "Objectively, the answer is clear: The person is not fit. If he shouldn't receive it, then it shouldn't be given."

But Arinze also made clear that decisions about whether to deny communion to Kerry and other U.S. politicians would be made by the U.S. Catholic bishops, not by the Vatican. "The norm of the church is clear. The Catholic Church exists in the United States, and there are bishops there. Let them interpret it," he said.

A spokesman for Archbishop Sean P. O'Malley of Boston said Kerry had not been barred from taking communion in his home town, and he indicated that no ban was likely.

"The position of Archbishop O'Malley has been that when people come forward to receive communion, we give them communion. The moment of communion is not the moment in which to raise the question of whether someone should or should not be receiving it," said the spokesman, the Rev. Christopher Coyne.

Coyne said that it would be appropriate for a priest or bishop to counsel a politician whose positions are contrary to church teachings. "But this is something that's handled privately with the Catholic," he said. "It's not something where you would make any kind of public action or public statement to withhold communion."

That appears to be in keeping with the approach of the vast majority of U.S. bishops, although a few have publicly threatened to withhold communion from certain politicians. Archbishop Raymond L. Burke of St. Louis said in January that he would deny communion to Kerry. Cardinal Theodore McCarrick of Washington, who met privately with Kerry last week, "is reluctant to use the Eucharist as a sanction," according to his spokeswoman, Susan Gibbs.

The Kerry campaign did not respond directly to Arinze's remarks and instead issued a statement saying that "Senator Kerry agrees with President Kennedy when he said, 'I do not speak for my church on public matters, and my church does not speak for me.' " Kerry, who has said he personally opposes abortion but supports a woman's right to choose, reiterated that position at a rally Friday with women's rights activists who are gathering in Washington for a march on Sunday.

"I believe that in the year 2004 we deserve a president who understands that a stronger America is where women's rights are just that: rights, not political weapons to be used by politicians of this nation," he said.

Raymond Flynn, a former Boston mayor and U.S. ambassador to the Vatican from 1993 to 1997, said that the Vatican and U.S. bishops were coming under "tremendous pressure from ordinary Catholics" to "do something about politicians who are exploiting their Catholic credentials and trying to ingratiate themselves with Catholic voters . . . when their voting record is completely inconsistent with the principles of the Catholic Church."

Flynn, a Democrat who now heads the group Your Catholic Voice, predicted that Arinze's comments would hurt Kerry, even if the cardinal avoided mentioning him by name. "This will receive attention by the 65 million Catholics in this country, and it will have a political impact," he said.

But Frances Kissling, president of Catholic for a Free Choice, said public opinion polls show that most U.S. Catholics share Kerry's position on abortion.

"I have seen no evidence that ordinary Catholics have a problem with elected officials who are pro-choice receiving communion," she said. "I think there are a number of relatively small, right-wing Catholic lay groups who have seized on this issue of Kerry and communion as a strategy for supporting the Republican Party."

The pope has said it is the duty of Catholic politicians to adhere to church doctrine in setting public policy, although he has not laid down guidelines for sanctioning those who ignore Vatican teaching.

Arinze introduced a 71-page Vatican document on liturgical abuses that seeks to stop lay people from taking on the role of priests, the insertion of non-Catholic rites into Masses and giving communion to non-Christians. An earlier proposal to discourage participation of altar girls was omitted.

The final instructions described the participation of boys as "laudable" -- a reflection of the belief among Vatican officials that service as an altar boy can aid recruitment into the priesthood -- but said that girls could serve as well.

Cooperman reported from Washington.

Sen. John F. Kerry, the presumptive Democratic presidential nominee, took communion on Palm Sunday at the Charles Street AME Church in Boston.