Italy has denied permission for U.S. military aircraft to land at the Sigonella air base in Sicily before flying to the Middle East, a source close to the matter said on Tuesday, confirming a newspaper report.

Daily Corriere della Sera reported that “some U.S. bombers” had been due to land at the base in eastern Sicily before heading to the Middle East. The newspaper did not specify when the aircraft were scheduled to arrive.

Corriere della Sera said permission was withheld because the U.S. had not sought authorisation and Italy’s military leadership had not been consulted, as required under treaties governing the use of U.S. military installations in the country.

Centre-left opposition parties have urged the government to block U.S. use of bases in Italy to avoid involvement in the conflict.

Prime Minister Giorgia Meloni’s right-wing government said it would seek parliamentary authorisation should any such requests be made.