France said on Monday that Algeria had threatened to expel 12 of its diplomatic staff and that it would take immediate reprisals should that occur in the latest flare-up between them.
Algeria protested over the weekend against Frances's detention of an Algerian consular agent suspected of involvement in the kidnapping of an Algerian. French media said three people, including the diplomat, were under investigation over the seizure of Algerian government opponent Amir Boukhors.
"The Algerian authorities are demanding that 12 of our agents leave Algerian territory within 48 hours," French Foreign Minister Jean-Noel Barrot said in a statement.
"If the decision to expel our agents is maintained, we will have no choice but to respond immediately."
There was no immediate confirmation from Algeria of an imminent expulsion.
France's relations with its former colony have long been complicated, but took a turn for the worse last year when French President Emmanuel Macron angered Algeria by backing Morocco's position over the disputed Western Sahara region.
Only last week, Barrot had said ties were returning to normal after a visit to Algeria.
