He stressed that the Syrian war was something the UK government "could have foreseen and done something about," adding that there had been many opportunities to intervene.
"We lack a political will in the West to intervene. We are beginning to learn the price of not intervening. We did not intervene in Syria, tens of thousands of people have been killed as a result… We have allowed a terrorist state to emerge in the form of [Daesh], which we now try to defeat. Key allies like Lebanon and Jordan are destabilized," Osborne added.
Over the recent months Aleppo, as the last large urban stronghold of militants in Syria, has become a major battleground in Syrian civil war. The government forces have recently been able to make significant progress in their offensive on eastern Aleppo.
Earlier in the day, Rupert Colville, spokesman for UN High Commissioner for Human Rights, said that the Syrian government forces and Iraqi militia allied with them allegedly killed at least 82 civilians in their offensive on the militant-held districts of the city of Aleppo.
Syria has been in a state of civil war since 2011, with government forces fighting Syrian opposition groups striving to overthrow the president. Damascus is also fighting numerous extremist and terrorist groups such as the Jabhat Fatah al Sham and Daesh, both outlawed in Russia. According to the United Nations, at least 300,000 Syrians have died since the beginning of the conflict.