Later on Sunday evening, a Syrian Air Force plane, a Russian-made Su-22, dropped bombs near SDF fighters in Tabqah and, the coalition said, "in accordance with rules of engagement and in collective self-defence of Coalition partnered forces, (the Syrian plane) was immediately shot down by a US F/A-18E Super Hornet".
Amping up rhetoric against United States actions in the area, Russian Federation said Monday it will consider aircraft west of the Euphrates River "air targets" and track them by air and on land.
The Syrian plane was shot down by a U.S. Navy fighter jet after attempting to bomb U.S. -allied coalition forces, according to the U.S. military.
It said the Coalition "does not seek to fight Syrian regime, Russian or pro-regime forces partnered with them, but will not hesitate to defend Coalition or partner forces from any threat".
The Russian Ministry of Defense called the downing of the plane "a cynical violation of the sovereignty of the Syrian Arab Republic" and "military aggression".
Frants Klintsevich, deputy head of the defense committee in Russia's upper house of parliament, said the defense ministry statement does not mean there will be war with the U.S.in Syria, but rather that Moscow will not accept attacks on its Syrian allies.
The U.S. -led coalition has in recent weeks escalated its aerial bombing campaign in northern Syria and Raqqa province.
Trump expresses more frustration over Russian Federation investigation
The Washington Post first reported the news on Wednesday evening. It's not clear who's operating the account. Trump tweeted Thursday afternoon.
Russian Federation backs the regime of Syrian President Bashar al-Assad in the country's ongoing conflict, and has called the USA strike a violation of Syrian sovereignty.
The Russian announcements came in response to the downing of the Syrian Air Force plane, which was the first time for the United States after it began fighting the IS in Syria, leading a coalition of worldwide forces, in 2014.
Using the "deconfliction line", the USA asked Russian Federation to "de-escalate the situation and stop the firing".
US -backed opposition fighters said Assad's forces have been attacking them in the northern province of Raqqa and warned that if such attacks continue, the fighters will take action.
And a top Russian official called the USA downing of the Syrian plane an act of aggression that assists terrorists. ISIS's capital of Raqqa is east of the river and is now the site of intense US operations in support of its allies' push on the city. The pilot ejected over the area controlled by terrorists, his fate is unknown.
On several occasions in recent weeks, warplanes of the US -led coalition have also struck pro-government forces to prevent them advancing from a USA -controlled garrison in southeastern Syria at a spot where the country's borders join with Iraq and Jordan. Israel also is concerned about Iran's missiles and has deployed a multilayered missile-defense system.