Spain has banned U.S. military aircraft involved in the Middle East war from using its airspace, reaffirming Madrid’s opposition to Washington’s operations in Iran.

Deputy Prime Minister Carlos Cuerpo confirmed the news on Monday, adding that the prohibition was in line with Madrid’s existing ban on the use of Spanish airbases for the U.S. and Israel’s military operations in the Middle East.

“This is part of the decision already made by the Spanish government to not participate in, or contribute to, a war which was initiated unilaterally and is against international law,” Cuerpo said in a radio interview with the Cadena SER station.

Defense Minister Margarita Robles said the ban had been in place from the start of the conflict, and had been made “perfectly clear to the American military” from the outset. “We don’t authorize either the use of military bases or the use of airspace for actions related to the war in Iran.”

It’s unclear how much of an impact Spain’s decision has on warplanes like the B-2 Spirit bombers making the transatlantic roundtrip from Whiteman, Missouri to Iran. Spanish authorities clarified that the planes still receive logistical support from Spain, and are allowed to enter Spanish airspace in emergency situations.

Spain’s Sánchez has led Europe’s opposition to the war in Iran. U.S. President Donald Trump has been infuriated by Madrid’s refusal to allow U.S. forces to use jointly-operated bases on Spanish soil to carry out its operations in Iran. Earlier this month he described Prime Minister Pedro Sánchez’s government as “terrible” and “unfriendly,” and threatened to cut all trade with the EU’s fourth-biggest economy.