The United States on Thursday moved to allay fears that it was questioning Spain’s sovereignty over Ceuta and Melilla, but criticized Prime Minister Pedro Sánchez’s government for its “refusal” to defend the North African exclaves from a “migrant invasion.”

Tens of thousands of migrants poured into Ceuta last week from Morocco in a surge that heightened Spanish fears about the vulnerability of its North African cities to hybrid attack.

Amid the crisis, Spanish politicians and media raised concerns about the warming relationship between Morocco — which claims Ceuta and Melilla — and the U.S. President Donald Trump, who was infuriated by Socialist Sánchez’s refusal to back the war in Iran.