The Vatican has turned down a proposal that Pope John Paul II stop off in Washington On his way to or from the Latin American bishops' conference in Puebla, Mexico, later this month.

According to a State Department spokesman, the idea for a U.S. stopover came from President Carter's special envoy to the Vatican, Robert Wagner. But Informal inquiries from the State Department to the Vatican indicated that an official invitation to the pope could not be accepted, so the matter was dropped.

Church officials here speculated that the pope would be reluctant to visit any country at the invitation of its political leaders.

Palu VI traveled extensively in the early years of his pontificate but, with the exception of a visit to the United Nations, his travels were prompted by religious events and in response to invitations from church leaders.

The present pope's trip to Mexico, his first journey abroad since his election as pope, is being made in response to an invitation from Latin American bishops rather than secular authorities.

The visit is, in fact, causing some consternation in government circles in the country which, though nominally Catholic, practices the strictest separation between church and state.

Anticlericalism in Mexico is reflected in the country's 1917 constitution, which bars clergumen from voting or participating in political meetings and even prohibits them from wearing clerical garb outside a place of worship.

The government has granted Pope John Paul a special exemption from the latter ruling, however permitting him to wear his pontifical robes at the Puebla conference.