In late October, US President Donald Trump made repeated statements about the importance of “securing” Syria’s oil.

The Russian Foreign Ministry, commenting on US plans to expand its military mission to protect Syrian oil, said that the territories of the country's oil fields should be controlled by the Syrian government.

The ministry further noted that Russia wouldn't cooperate with the US on the issue of Syrian oil.

"We will not cooperate with the US on the issue of the Syrian oil," Russian Deputy Foreign Minister Sergey Vershinin said.

"Syrian oil is a national asset of all Syrians. [Russia] believes that Syrians should control their own natural resources, including oil," the deputy foreign minister added.

On Tuesday, the Turkish news agency Anadolu reported that the US military was building two new bases in the oil-rich province of Deir ez-Zor in northeast Syria. US President Donald Trump earlier said that the contingent of US troops would ensure the security of oil fields in eastern Syria. Vershinin said on Tuesday that such actions were "unacceptable”.

President Trump has repeatedly referred to the need to secure and hold Syria’s oil resources, with Pentagon Chief Mark Esper confirming last week that US troops’ mission was to "deny" the oil to Daesh and "other actors in the region".

In late October, the Russian Defence Ministry revealed that Russian military intelligence had discovered “leading American corporations”, working together with private military contractors and supported by US Special Forces and airpower, were generating over $30 million a month in revenues by smuggling the commodity out of Syria from the oil-rich province of Deir ez-Zor.