The Syrian military has received new Russian-supplied air and ground weapons, according to a Syrian source that spoke with Reuters Thursday. The revelation comes amid concerns that Moscow's arms deliveries to docks and airports on Syria's Mediterranean coast in recent weeks would destabilize the war torn country further. 

"New weapons are being delivered, and [they are] new types of weapons. The Syrian army is being trained in the use of these weapons. In fact, the army has started using some of these types," said the Reuters source.

Russia has long been a political supporter of Syrian President Bashar Assad's authoritarian regime and has sold the country Russian-built weapons consistently for more than 10 years. However, a recent increase in weapons deliveries from Russia underlines the desperate military position Assad is now facing. Russian has also increased its own footprint in the region by establishing what the White House has called a "forward operating base" at a Syrian local airport, while it has also significantly increased the use of a naval port in Syria. 

U.S. officials claimed to have identified a range of Russian military equipment inside Syria -- including battle tanks and attack helicopters -- and stated that Russia has been landing around two flights per day at Syria's Latakia airport. 

The Reuters source, who was not named, said that the weapons were varied, and troops had begun training with them months ago and started using them recently. "The weapons are highly effective and very accurate and hit targets precisely," the source told Reuters. "We can say they are all types of weapons -- be it air or ground."

The Syrian military, which has faced severe manpower shortages this year, lost ground to its enemies all across the country, including the Islamic State Group and other insurgent groups that want to see Assad removed from power. Despite the turmoil inside the country, Assad told Russian TV Wednesday that he would not step aside as leader of Syria. 

The four-year war in Syria has killed more than 250,000 people and displaced an additional four million.