Footage circulated on the Syrian presidency’s Facebook page shows Assad in the cockpit of a Russian Sukhoi SU-35 warplane.
He also inspected weapons, personnel and armoured vehicles at the base near Latakia, in western Syria.
Assad reportedly wrote in the visitor’s book: ”The Syrian people will not forget that its Russian brothers stood next to them in this national war.”
The Syrian president toured the base, which has been at the heart of Moscow’s military effort in support of Assad since 2015, accompanied by Russian chief of staff General Valery Gerasimov.
Vladimir Putin has continued to back his ally Assad despite repeated criticisms from the West.
Later at a hearing before the US House of Representatives, she added: “I believe that the goal is at this point not just to send Assad a message but to send Russia and Iran a message that if this happens again we are putting you on notice.”
The White House revealed yesterday that it had identified potential preparations by Assad’s government for another chemical weapons attack on Syria.
Donald Trump’s administration warned if Assad conducts another attack using chemical weapons on his people, “he and his military will pay a heavy price”.
A White House statement said: “The United States has identified potential preparations for another chemical weapons attack by the Assad regime that would likely result in the mass murder of civilians, including children.
“If, however, Mr Assad conducts another mass murder attack using chemical weapons, he and his military will pay a heavy price.”