The two 17-year-olds are suspects in a case involving a violent assault on a Portuguese youth in August in Ponte de Sor, near Portalegre in the Alentejo region, that left him in hospital with serious injuries. Prosecutors want to question them about the incident and had asked the Ministry of Foreign Affairs to seek the lifting of their immunity for the purpose.

Santos Silva declined to say what steps the government would take if Iraq does not respond to the request in time.

"I'm waiting for a response from the Iraqi authorities, who are considering and should respond," he told journalists in a break from a diplomatic event in Lisbon. "I trust that it will come and then I shall analyse its contents."

Asked what he would do if Iraq does not reply by midnight on Thursday, Santos Silva repeated that he was "awaiting the response".