DAMASCUS, Jan. 9 (Xinhua) -- Syrian President Bashar al-Assad has said that his mission is to liberate every inch of Syria, state news agency SANA reported on Monday.

"Our mission, according to the constitution and laws, is to liberate every inch of the Syrian territory," SANA quoted the president as telling several French reporters Sunday.

"This is, undoubtedly, not a subject for debate," Assad said.

The president made the remarks as his army had wrested full control over the northern city of Aleppo after the rebels' withdrawal to the countryside.

Assad considered the Aleppo victory as "an important station toward the victory in the war imposed on Syria."

Commenting on the destruction of the formerly rebel-held eastern part of Aleppo, Assad said there is no good war throughout history.

"Every war is bad," he said. "Why bad? because every war involves destruction..., involves killing. That's why it's bad we cannot say this war is good, even if it was for a noble purpose, which is defending your homeland."

Still, Assad said that civilians need to be set free from the "oppression and control" of the "terrorist groups."

On the recently established cease-fire, which was brokered by Russia and Turkey in late December, Assad said that the truce didn't hold in several Syrian areas.

"We can say that there is a viable cease-fire when all parties cease the fight, and this didn't happen in several Syrian areas."

"There are daily breaches to the cease-fire, including in Damascus, because the terrorists control the main water source feeding Damascus, and deprive over 5 million civilians from water for three weeks," Assad said, referring to the Barada Valley area.

Rebels in Barada Valley were accused by the government of cutting off drinking water from Damascus since Dec.23. The rebels, for their part, accused government forces for the damage that has befallen the Ain Fijeh springs, the main water source for Damascus.

The government said the rebels in Barada area are with the al-Qaida-linked Nusra Front, which is not included in the cease-fire, as the group, alongside the Islamic State (IS) group, are designated as terrorist groups by the United Nations.

However, several rebel groups, angered by the ongoing military operations in Barada, announced that the cease-fire across Syria is finished, citing what they called the government forces' repeated breaches in Barada Valley.

It wasn't immediately clear how such remarks and stance will affect the shaky truce and the planned peace talks scheduled to take place in Astana, Kazakhstan, which are also part of the recent Russian-Turkish agreement.

The Syrian government said it would take part in the Astana talks, but some rebel groups spoke of "freezing" the talks in the Kazakh capital.

Assad, in his remarks to reporters, said his government is ready to negotiate everything in Astana.

"When we talk about the negotiations on ending the conflict in Syria, or the future of Syria, everything is available and there are no limits to such negotiations," Assad said.

He, however, remained skeptical about "the other party" at the upcoming talks.

"But who is the other party, we don't know yet... Will it be a real Syrian opposition? When I say real, I mean that it should have popular support in Syria, not based in Saudi Arabia, or France, or Britain," Assad said, in an apparent jab at opposition groups the government says are linked to foreign agendas.

"It should be a Syrian opposition to discuss Syrian issues and thus the success, or the viability, of the conference (in Astana) relies largely on this point," he said.

Asked about his presidency, whose discussion was labeled as a red line by his government, Assad said his post is related to the constitution.

"The constitution is very clear in terms of the mechanisms of the arrival or departure of the president and thus if they (opposition) want to discuss this point, they need to discuss the constitution, which is neither a property of the government, nor of the opposition, but of the Syrian people," he said.

He said the opposition "can't say we want this president or we don't want that president," because the president is elected through the ballot boxes.

"If they don't want him, let's go to the ballot boxes and let all the Syrian people chose a president."