His written statement was published on the Syrian presidency's Telegram channel and dated December 16 from Moscow, where he has been granted asylum.
He was ousted after insurgent forces led by the Islamist Hayat Tahrir al-Sham swept through Syria in a lightning offensive, ending more than 50 years of iron-fisted rule by his family.
"At no point during these events did I consider stepping down or seeking refuge, nor was such a proposal made by any individual party," Assad said in the statement detailing the circumstances leading to his departure from Syria.
He said he had remained in the capital Damascus, carrying out his duties until the early hours of Sunday, December 8.
"As terrorist forces infiltrated Damascus, I moved to Latakia in co-ordination with our Russian allies to oversee combat operations," he said.
But upon arriving at the Russian air base of Hmeimim that morning "it became clear that our forces had completely withdrawn from all battle lines and that the last army positions had fallen".
Bashar al-Assad left Damascus and moved to a Russian base in Latakia, a statement says. (AP PHOTO)
The Russian military base came "under intensified attack by drone strikes" and "with no viable means of leaving the base, Moscow requested that the base's command arrange an immediate evacuation to Russia," the statement said.
The Kremlin said on December 9 that President Vladimir Putin had made the decision to grant Assad asylum in Russia, which deployed its air force to Syria in 2015 to help him repel rebel forces.
Reuters reported last week that Assad confided in almost no one about his plans to flee Syria.Â
Instead, aides, officials and even relatives were deceived or kept in the dark, more than a dozen people with knowledge of the events told Reuters.
