The long-running dispute over construction of the $1.7 billion plants in the Uruguayan town of Fray Bentos has soured relations between the two countries. Protesters have blocked bridges over the Uruguay River, which forms the border between Argentina and Uruguay and which opponents say will be poisoned if construction of the two mills proceeds.

During the Easter weekend, Kirchner opened the way for bishops from the two South American neighbors to broker dialogue.

"I would be delighted if the two churches could help," he told the Argentine newspaper Clarin.

No formal church mediation has yet been scheduled, but Father Jose Luis Sanchis, parish priest in Fray Bentos, said there had been informal contacts between clerics in both countries, and there was a willingness to foster talks.

"We understand that it is a problem with economic, technical and political aspects, and the church is not a specialist in any of those," Father Sanchis said.in a telephone interview. "But the church is a specialist in humanity, in building bridges."

The state-of-the-art pulp mills planned by Finnish company Botnia and Spain's ENCE represent the biggest foreign investment in Uruguayan history. ENCE has heeded a call by Kirchner for a three-month halt to work pending further environmental studies, but Botnia has refused, sparking fresh protests in the Argentine town of Gualeguaychu, where environmentalists are planning a demonstration for April 30.

Archbishop Nicolas Cotugno Fanizzi of Montevideo, Uruguay, took up the theme in his Easter homily. He said he and Cardinal Jorge Bergoglio of Buenos Aires, Argentina, had met recently in Argentina to seek ways of calming tensions.

"What the archbishop of Buenos Aires and the archbishop of Montevideo want, concretely, is to build bridges between Argentines and Uruguayans. And if it is possible, useful and appropriate, we can be at everyone's service to facilitate those bridges," he said in his service in the Montevideo cathedral.

Argentine Bishop Jorge Lozano of Gualeguaychu echoed Argentine clerics' willingness to help and did not rule out a possible meeting with Uruguayan bishops soon to "share concerns." He said he had already spoken by telephone with Bishop Pablo Galimberti di Vietri of San Jose de Mayo, president of the Uruguayan bishops' conference, and other church leaders.

As a sign of good will, Bishop Lozano said Uruguayan Bishop Carlos Collazi Irazabal of Mercedes, another town near the Uruguay River, had sent him the olive branch used in the town's Palm Sunday procession.

Church leaders from Argentina, Uruguay, Brazil and Paraguay are due to meet in Brazil in May for a meeting of border dioceses, and Father Sanchis said the pulp mills dispute was on the agenda.

He said the subject was of great concern to his parishioners. The mills are not expected to be major employers once the construction phase is over because they are so high-tech and because the more labor-intensive paper processing will not be done in Uruguay, he added.

Father Sanchis interpreted Kirchner's invitation for church mediation as an appeal for fresh impetus to settle a dispute that has become increasingly radical and "rather irrational." He said Uruguay is officially a secular state in which the church has not traditionally played a conflict-mediation role.

Father Sanchis said he believed the authorities in the Argentine province of Entre Rios, which flanks the Uruguay River, "thought things were going to have been easier. At first they didn't take (the protests) seriously, they practically treated them like a game, and now they have realized that people are entrenched in their positions and it's going to be a lot more difficult to get them to relent."

But he said he remained hopeful that a solution could be found, especially because it was "practically impossible" to halt the pulp mills project without the Uruguayan government incurring hefty penalties for breaking the contract.