Senior representatives from the USA and Russian militaries met in an undisclosed location "somewhere in the Middle East" to discuss the tensions surrounding the anti-ISIS fight in Syria, the AP reports.
The country's defence ministry said Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab militias fighting, had taken up positions on the eastern banks of the Euphrates alongside United States special forces.
Dillon warned that the meeting did not suggest that the U.S.is cooperating with either the Russians or the Syrian regime and that the meeting focused on the prevention of "accidental targeting or other possible frictions". "They had a face-to-face discussion, laid down maps and graphics", said Army Colonel Ryan Dillon, a Baghdad-based spokesman for the USA -led coalition, adding it appeared to be the first meeting of its kind.
Dillon, addressing a Pentagon briefing, disclosed few details, including who participated in the meeting or its precise location.
The militants of the Daesh terrorist group (outlawed in many countries) control almost 80 percent of oil fields and most gas deposits in the Syrian province of Deir ez-Zor, the Syrian Gas Company representative in the region, Amin Hamid, told Sputnik.
A military source, speaking on the condition of anonymity, said that army units also made advances towards Ma'adan city in the eastern countryside of Raqqa province.
The Syrian army, backed by Russian and Syrian war planes, has captured about 62 miles of the west bank of the Euphrates this month, reaching the Raqqa provincial border earlier this week, the Syrian Observatory for Human Rights reported.
Without facing the Islamic State, the so-called Syrian Democratic Forces, a US-backed Kurdish-Arab alliance, meanwhile moved south of their positions on the M7 motorway and controlled the oil and gas fields of Tabiyeh and Al- Isba, according to the Al-Masdar News portal.
Russia's Defence Ministry subsequently said the waters of the Euphrates had risen as soon as the Syrian army began crossing it, suggesting this could only have happened if upstream dams held by the USA -backed opposition had been opened.
The Russian Ministry of Defense has released aerial images which they say show US Army special forces equipment north of the town of Deir er-Zor, where ISIS militants are deployed.
The U.S. -backed militias said on Saturday they had come under attack from Russian jets and Syrian government forces, something Moscow denied.
Syrian troops supported by Iranian-backed militias have also crossed to the eastern side of the river, which runs through the city of Deir Ezzor, increasing their presence in an area where US-backed fighters have also advanced.
"Despite the strongholds of the U.S. armed forces being located where ISIS troops are now deployed, there are not even signs of the organization of a battle outpost", the Russian Ministry of Defense said.