In an interview with Portuguese broadcaster RTP, Assad said the image of him presented in the West was deeply skewed.
"The people are against him, the regional countries are against him and the West is against him, and (still) he succeeded," Assad said, speaking in English.
"You're either lying to us or you're talking about Superman because if you don't have Superman, (if) he's a regular president, it means he could withstand four years only because he has the public support."
Assad's regime has been fighting a multi-front civil war with a range of opposition factions including jihadists after an uprising erupted in Syria in March 2011.
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Estimates have put the number of dead at more than 220,000, but Assad rejected that figure.
"That number is exaggerated, always the West has exaggerated the numbers in Syria," he said.
He also denied any suggestion that Syria had collapsed into a failed state.
"We still have the institutions working, we still have the subsidies, we still pay the salaries... even in some areas under the control of the terrorists," Assad said.
"Syria is not finished and we don't have a failed state."
He said he supported a "political" solution to Syria's conflict but that much of the opposition was beholden to foreign backers, including Gulf countries, and he preferred to speak to "people who represent Syrians in Syria".