Egypt's defence minister Abdelfattah al-Sisi has warned that the current political crisis could push the state to collapse if conflicting political parties don't work together to solve it. Speaking to students at the Military Academy on Tuesday, he said, "The continuation of the conflict between political powers may lead to the collapse of the state, and threatens the future of the coming generations." He added that the deployment of the Armed Forces in Port Said and Suez is aimed at "protecting vital and strategic targets, most importantly the Suez Canal, to which we will not allow any harm, and to assist the interior ministry, which is carrying out its role very courageously and honourably." His remarks were published on the official Facebook page of the Armed Forces spokesperson. Al-Sisi said the economic, political and social challenges facing the country represented "a real threat to the security of Egypt and the cohesiveness of the Egyptian state" and the army would remain "the solid block" on which the state rests. He also said that protests must be kept peaceful, pointing to what he claimed was the difficult balancing act that the Armed Forces had to perform by allowing protests while at the same time protecting vital state facilities. Al-Sisi was appointed by President Mohammed Morsi after the army handed over power to the new president in June. Morsi sacked Field Marshal Hussein Tantawi, who had been in charge of Egypt during the transition and who had also been Hosni Mubarak's defence minister for 20 years. Political opponents spurned a call by Morsi for talks on Monday to try to end the violence. Instead, huge crowds of protesters took to the streets in Cairo and Alexandria, and in the three Suez Canal cities - Port Said, Ismailia and Suez - where Morsi on Sunday imposed state of emergency and a night curfew.