The Knights of Columbus is urging its members and other US Catholics to pray a novena from October 30 to November 7, the eve of election day.

"The Church teaches that Catholics are called to form their consciences based on Church teaching and vote in accordance with that well-formed conscience," said Supreme Knight Carl Anderson, who is CEO of the international fraternal organisation based in New Haven.

"Pope Francis has said in reference to the US election that we should 'study the proposals well, pray and choose with your conscience,' and this novena is designed to help Catholic Americans do that," Anderson said in a statement.