Pope Francis's funeral will be held on Saturday, the Vatican announced Tuesday, as world leaders from US President Donald Trump to Ukraine's Volodymyr Zelensky said they would attend to honour the Catholic leader.

The Argentine pontiff, 88, died on Monday from a stroke, less than a month after returning home from five weeks in hospital battling double pneumonia.

His funeral, which is expected to draw huge crowds, will take place at 10:00 am (0800 GMT) on Saturday in the square in front of St Peter's Basilica at the Vatican.

Francis's coffin -- which he previously ordered should be of wood and zinc -- will then be taken inside the church and from there to the Rome basilica of Santa Maria Maggiore for burial.