The Spanish interior minister said on Friday he hoped a diplomatic spat with Morocco over an influx of illegal migrants into Spain's North African enclave of Ceuta would soon end.

Morocco had appeared to loosen its border controls with Ceuta for two days on Monday, letting thousands of migrants pour into the enclave. The move was widely viewed as retaliation for Spain's hosting of Western Sahara independence leader Brahim Ghali.

Spain has said Ghali was admitted as a COVID-19 patient to a Spanish hospital last month under an assumed name and an Algerian diplomatic passport for humanitarian reasons.

"There was a disagreement (with Morocco) and we hope this disagreement will be as short-lived as possible," Interior Minister Fernando Grande-Marlaska told COPE radio station.

"It is inconceivable that a humanitarian gesture should trigger a situation like the crisis in Ceuta."

Ghali's Algeria-backed Polisario Front is fighting for the independence of Western Sahara, a territory once held by Spain and under Moroccan control since the 1970s.