"Our forces will demonstrate the capability to deploy rapidly, assault a target with integrated air and ground forces and conduct a rapid exfiltration anywhere in the OIR combined joint operations area", said Navy Capt. Bill Urban, spokesman for U.S.
Al-Tanf is a military base located 24km to the west from the al-Tanf border crossing between Syria and Iraq in Homs Governorate.
On Saturday, the Russian Defense Ministry claimed to have captured a group of militants who said they had a training camp near the American military base in At Tanf.
Most recently, the coalition told Rudaw English regarding reported strikes on Iranian forces in the area on September 3, "sometimes there are delays on strikes being reported".
Launching an attack with such weapons in a US-protected area would likely lead to an escalation in sporadic violence in the region, United States defence officials said.
The report further underlined that Moscow's warning has sharply raised United States commanders' concerns that American troops would be at risk if a Russian attack goes forward, prompting Washington to warn Moscow "not to challenge the USA military presence".
The Kremlin, which alleges that the US-led coalition base protects nearby militant troops, reportedly delivered two warnings in the past week, according to USA officials. "We are postured to respond", said one USA official.
The exercise comes after Moscow, on September 1, had warned for the first time that it would enter a restricted area in southern Syria, where the United States troops are located. "However, the United States will not hesitate to use necessary and proportionate force to defend U.S., coalition or partner forces, as we have clearly demonstrated in past instances", he said.
Russian warplanes have been carrying out intense airstrikes in Syria's northwest, pounding rebel-held areas in Idlib province and surrounding regions that have become the last sanctuary for the opposition.
"The U.S. does not require any assistance in our efforts to destroy [Islamic State] in the At Tanf deconflicition zone, and we advised the Russians to remain clear", Brown said.
The US warned Russian Federation that it would defend itself if attacked.
Al Tanf is home to a U.S military outpost where USA forces train local anti-ISIS partners.
"The situation is as it is now in Idlib because the countries sponsoring terrorism do not want to distinguish between terrorists and armed opposition", he said, a likely allusion to USA -backed Kurdish forces or Syrian rebels whom the Assad government accuses of being affiliated with Al Qaeda. Tensions were raised in February after dozens of Russian mercenaries were killed during a failed assault on a US-held position near the city of Deir al-Zor.