Both nations are seeded, but were put in the same path following proceedings in Geneva.
Italy will host North Macedonia in their semi-final, and will take on the winners of Portugal against Turkey in the final.
It is a blow to both nations, who just missed out on qualification from their respective group stages. Italy failed to beat Northern Ireland in their final group match and therefore ceded automatic qualification to Switzerland, while Portugal lost a winner-takes-all encounter at home to Serbia to drop into the second spot in their pool.
Italy, the reigning European champions, were one of the heavyweights in the draw, while Portugal – whose talisman Cristiano Ronaldo is expecting to play in the World Cup one last time – were one of the top-ranked teams.
The winner of the Portugal v Turkey match will host either Italy or North Macedonia in the final.
Russia and Poland will meet in Moscow for the right to play either Sweden or Czech Republic, who will do battle in Solna. The Russians were pipped to automatic qualification by Croatia in their group, while the Poles finished a distant second behind England. Sweden were edged out by Spain, while Czech Republic made it into the play-offs by virtue of their Nations League performance.
The semi-finals are due to be played on Thursday, March 24, with the finals slated for Tuesday, March 29.