Russian Federation is highly supportive of Syria's government and the forces loyal to it, but the Kremlin is also concerned about inviting a counterattack from Israel or its backer, the United States, which could happen if Iran gets involved.
"This is the first option. If not, we're going to resort to. liberating those areas by force, ' he said, adding 'the Americans should leave, somehow they're going to leave".
It remains unclear, however, under what circumstances the troops will eventually leave and what will happen to their Kurdish allies, who say they are determined to maintain control over the area. "They have to learn this lesson".
"The Russians do not want the Iranians to become too powerful in post-ISIS Syria", he said, referring to the multinational effort to crush the extremists that captured swaths of Syria and Iraq in 2014.
The southwest region is home to tens of thousands of people and forms a centre of the resistance. The agreement would envisage the pullout of all Iranian forces from the area and require Syrian rebels to surrender heavy weapons.
Syria also appeared to back creating a buffer zone on its southern border with Israel that would be free of Hezbollah and Iranian-backed forces, Saudi newspaper Al-Sharq Al-Awsat reported on Monday.
"The fact that Russia allows Israel a little bit of freedom to act to side-line Iran, Israel is doing it for the Russians", he said. He did not explain why this would cause panic in Israel.
Bashar al Assad has reacted to being called "Animal Assad" by US President Donald Trump with a phrase usually heard in school playgrounds.
Amir's double strike sparks England collapse in first Test
Coverage: Ball-by-ball Test Match Special commentary on BBC Radio 5 live sports extra, Radio 4 LW and the BBC Sport website. And we have to bat better. "I'm very proud of my team, the way the young players produced their talent", he said.
Assad reiterated the regime's denial that it carried out the attack in the eastern Ghouta town of Douma, saying that the regime did not have chemical weapons and it would not have been in its interest to carry out such a strike.
The disputed area is primarily to the east of the Euphrates River, along the northern border which Syria shares with Turkey. In the process, the Kurds have assumed de facto control over a vast area of mostly desert terrain amounting to almost a third of Syrian territory.
The most intense round of Israeli strikes so far took place earlier this month with a barrage of fire hitting Iranian positions as rockets fired from near the occupied Golan Heights targeted an Israeli position.
Jordan has always been anxious about the presence of Iranian-backed militias along its border, as has Israel.
On April 9, an Israeli airstrike against the T-4 airbase in Syria's Homs Province killed more than a dozen people, including seven Iranian military advisors.
Striking targets in Syria and threatening to assassinate the leader on the pretext of fighting Iranian influence is a sign that Israel is in "panic" after losing its "dear" terrorist assets, President Bashar Assad told RT.
"We were close to have direct conflict between the Russian forces and the American forces", Assad said in the interview.
A Syrian government offensive against Syria's rebel-held southwest-a region spanning parts of Daraa and Quneitra provinces-would shatter almost one year of calm in the region after the implementation of a American-, Russian- and Jordanian-backed de-escalation agreement in July 2017.