Pope Francis said on Monday that migrants were being exploited as "pawns" on a political chessboard in an apparent reference to the crisis at the Belarus border.
Thousands of migrants are stuck on the European Union's eastern frontier in what the EU says is a crisis Minsk engineered by distributing Belarusian visas in the Middle East, flying them in and letting them go to the border.
In a video message for the Geneva-based International Organisation for Migration's (IOM) 70th anniversary, Francis said denying migrants their basic dignity was against the tenets of most religions.
"Even more regrettable is the fact that migrants are increasingly being used as bargaining chips, as pawns on a chessboard, victims of political rivalries," Francis said.
"How can suffering and despair be exploited to advance or defend political agendas? How can political considerations prevail when it is the dignity of the human person that is at stake?" he said.
Poland and other EU nations say the crisis is part of a "hybrid war" Belarus is waging in retaliation for EU sanctions imposed in response to Belarusian leader Alexander Lukashenko's crushing of protests against his disputed re-election last year and is designed to destabilise the bloc.
Lukashenko has accused the EU of deliberately provoking a humanitarian crisis that needed to be resolved.
Latvia, Lithuania and Poland, bearing the brunt of the crisis, have deployed thousands of border guards, soldiers and police to seal the border and push back migrants attempting to cross over from Belarus.
Francis has made the defence of migrants and refugees a cornerstone of his papacy and in his message to the IOM said that beyond the political and legal aspects of irregular situations, "we must never lose sight of the human face of migration".
Belarus has begun to fly some migrants home, mostly to Iraq, but has said it is waiting for an answer from the EU on its demand that Germany should accept 2,000 stranded at the border, which the EU has rejected and Germany has denied agreeing to it.
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