Syrian President Bashar Assad told state media Thursday that defeating rebel forces would be a milestone in the fight against the opposition, but it would not immediately end the ongoing civil war.

Government forces, backed by Russia, Iran and paramilitary allies, have retaken most of Aleppo, formerly held by Western- and Gulf-backed opposition groups seeking to overthrow Assad in the conflict that has lasted more than five years. As the Syrian military closed in this month on the last remaining opposition-held pockets of the besieged city, Assad commented on an expected victory in Syria's former largest city and symbolic capital of the opposition movement.

"To be realistic, this does not mean the end of the war in Syria, but a huge step toward that end," Assad told Syrian newspaper Al Watan. "It does not end until all terrorists have been completely eliminated ... and we will continue the war against them."

Aleppo has frequently been subject to bombardment on both sides with near-constant Russia and Syrian airstrikes in recent weeks, allowing recent gains made by the Syrian army to place Assad in what may be his most advantageous position since the beginning of the war in 2011. Despite losing more than 75 percent of their territory in Aleppo, rebel groups rejected any proposals to surrender or retreat from the city.

Instead, opposition groups responded to government advances by attempting to negotiate a five-day ceasefire for what they claimed to be humanitarian purposes. Damascus ruled out the possibility of any ceasefires, claiming opposition fighters would use the pause to regroup.

At the U.N. Security Council, Russia and China vetoed Monday a proposed week-long cessation of hostilities. A rebel mortar attack killed two Russian nurses at a field hospital that same day.

Meanwhile, U.S. Secretary of State John Kerry and his Russian counterpart, Sergei Lavrov, were involved in negotiations regarding the evacuation of civilians from the city and delivery of crucial assistance to those trapped inside. Violence has displaced tens of thousands in the past week alone, and severely restricted access to aid has threatened the lives of those remaining.

Both sides of the conflict blame each other for putting civilians at risk.

RTSV6R5 Syria's President Bashar al-Assad speaks during an interview with Al Watan newspaper in Damascus, Syria, in this handout picture provided by the Syrian Arab News Agency on Dec. 8, 2016. Photo: Reuters