On Thursday an anti-Assad group in Syria's south confirmed to Reuters via its 'rebel' commander that it is conducting rare military exercises with American forces in order to "send a strong message to Russia and Iran that the Americans and the rebels intend to stay and confront any threats to their presence," according to a new Reuters report.

The anti-Assad commander, Colonel Muhanad al Talaa, is part of the Pentagon-backed Maghawir al Thawra group now conducting eight days of "live-fire and ground assault" drills that involve "hundreds" of U.S. troops and allied Syrian insurgents cooperating together.

Official US defense media accounts released new photos showing the drills near At Tanf in action. via CENTCOM

“These exercises have a big importance and have beefed up the defenses of the area and raised the combat capabilities and morale and that of civilians in the area,” Talaa said in a statement from Tanf.

The US appears to be responding to the major Russian naval and amphibious assault drills along Syria's coast from last week. This also comes after Moscow warned its forces could attack in the area near US-occupied At Tanf in pursuit of al-Qaeda linked jihadists that Russia says hides out under US protected areas.

The U.S. military has said in recent statements that it is not seeking military confrontation with Russia, and a spokesman said US coalition commanders maintain “deconfliction” channels with Moscow's forces to prevent “miscommunication or escalate tension”.

Part of the newly releasted photo set showing the drills near At Tanf in action. via CENTCOM

“The exercise was conducted to reinforce our capabilities and ensure we are ready to respond to any threat to our forces within our area of operations’” Colonel Sean Ryan stated of the Marine-Syrian rebel exercises, according to Reuters.

American forces have enforced a 55 km (35 mile)-radius “deconfliction zone” around its garrison in At Tanf, which has been declared "off-limits" to others.

Meanwhile both Russia and Syria have condemned the presence of the base and others as a clear violation of Syrian sovereignty, and have lodged multiple formal complaints the UN Security Council, which have been routinely rebuffed or ignored.

A new photo set was released by Department of Defense (DoD) official media accounts in clear signal to Moscow and Tehran...

The 'rebel' commander now fighting alongside the Marines told Reuters further that, “We are staying whether the Russians or Iranians want or not.”

“If Tehran does not respond to the demands of the Americans there is a big likelihood they will be hit. It’s inevitable the Iranians leave Syria. This should happen quickly and in a decisive way,” he added.