Pope John Paul II has included two American cardinals in the group of 20 churchmen he appointed this week to participate in the extraordinary synod of bishops that begins Nov. 24.

They are Cardinal John Krol of Philadelphia and Cardinal Bernard Law of Boston. Krol will serve as one of three synod co-presidents. The papal appointees, together with the heads of national conferences of bishops throughout the world and heads of the Roman Curia, the Vatican administrative offices of the church, bring to 164 the number of synod participants. The pontiff may still name eight more participants under rules of the synod.

The U.S. delegation will be headed by Bishop James Malone of Youngstown, Ohio, president of the National Conference of Catholic Bishops.

Observers from 10 other Christian denominations will be invited to attend the synod, which will examine the results of Vatican Council II.

Bishop Jan Schotte, secretary general of the synod, told a news conference that the invitations were intended to stress the Roman Catholic Church's work toward Christian unity, which was a main subject of the council that ended 20 years ago.

Schotte declined to say which 10 denominations would be invited to send observers, saying the Vatican's Secretariat for Christian Unity is still in the process of contacting them.

Earlier this week, the pope reiterated his commitment to the reforms introduced by the council 20 years ago.

He also announced that he will speak about the council in his regular noon appearances in St. Peter's Square each Sunday until the start of the extradorinary synod.