In the latest escalation between the U.S. and the forces loyal to Syrian President Bashar Assad, a U.S. F-15 fighter jet shot down an Iranian drone over southern Syria on Tuesday. The move was the second time in a week that it shot down a pro-Syrian government aircraft in the sky.

"The armed pro-regime Shaheed-129 UAV was shot down by a U.S. F-15E Strike Eagle at approximately 12:30 a.m. local time (5:30 p.m. EDT) after it displayed hostile intent and advanced on Coalition forces," according to the press release from Combined Joint Task Force – Operation Inherent Resolve.

Carla Babb, the Pentagon correspondent for Voice of America (VOA) tweeted Tuesday saying the sources have confirmed that the Iranian-made drone shot down by the U.S. fighter jet was being operated by the Iranian Revolutionary Guards Corps.

Pentagon spokesman Navy Captain Jeff Davis said the U.S. military shot down the Shahed 129 as it approached an established coalition combat outpost near al-Tanf in southeast Syria, where the U.S. is holding training sessions for local fighters against the Islamic State group, VOA reported.

ReadUS Shoots Down Syrian Jet, Iran Bombs ISIS In Retaliation For Tehran Attacks

Officials also said that the shot Iranian aircraft was the same type of drone that a U.S. warplane had shot down June 8 after it attacked U.S.-backed fighters in southern Syria. U.S. officials said it remained uncertain as to who was operating the drones — Whether it was Shiite militia fighters, Syrian officers or Iranian advisers. The confrontation was the latest clash in Syria where a proxy war is going on between Iranian-backed militias that support Assad and the Syrian fighters who have been trained by the U.S., British, and other coalition military advisers, the New York Times reported.

U.S.' downing of the Iranian drone came on the same day when Australia announced it is temporarily suspending airstrikes by its forces in Syria after a threat from Russia. The Russian Defense Ministry said Tuesday it would exert new control over the skies of western Syria in response to the downing of a Syrian fighter jet by the U.S. Air Force on Sunday, reports said.

"From now on, in areas where Russian aviation performs combat missions in the skies of Syria, any airborne objects found west of the Euphrates River, including aircraft and unmanned vehicles belonging to the international coalition, tracked by means of Russian land and air anti-aircraft defense, will be considered air targets," CNN reported citing the Defense Ministry statement.

Read: Hundreds Of Civilians Have Been Killed In Syria By US-led Airstrikes

Despite U.S. airstrikes, Iranian militias have continued to encroach on the U.S.-supported forces at al-Tanf. The U.S. military has established a roughly 50-kilometer “deconfliction” ring around al-Tanf and has warned the pro-Assad forces — through a Russian deconfliction channel — that movement within the zone could be considered hostile and the Iranian drone was outside that deconfliction area when it was shot down, the Washington Post reported citing a U.S. defense official.