In a wide-ranging interview in Damascus with the Mail on Sunday, Assad slammed the United States and British military actions in Syria as "colonial" while praising supporter Russia.
"We've had good relations with Russia for more than six decades now, nearly seven decades. They never, during our relation, try to dictate, even if there are differences," he told the British newspaper.
Assad admitted his government has disagreed with Russia and Iran throughout the country's seven-year conflict.
"That's very natural, but at the end the only decision about what's going on in Syria and what's going to happen, it's a Syrian decision," he said.
Moscow intervened militarily in Syria's conflict in 2015, when Assad's forces were struggling to hold territory against rebel fighters.
Russian air strikes and military advisors have since helped regime troops seize back more than half the country.
Tehran, too, has sent military advisors to Syria, but Assad has denied that Iranian troops are on the ground.
Iran's regional foe, Israel, has repeatedly warned it will not accept an entrenched Iranian presence in Syria.
It is suspected of carrying out numerous raids on Syrian government positions over the years, and last month announced unprecedented strikes on what it said were Tehran-operated bases in Syria.
In his interview, Assad denied Moscow had ever had prior knowledge of such strikes, despite close cooperation between Israel and Russia.
"No, no, that's not true," he said.
"Russia never coordinated with anyone against Syria, either politically or militarily, and that's (a) contradiction," he said.
"How could they help the Syrian army advancing and at the same time work with our enemies in order to destroy our army?"
Syria's war has also drawn in many Western powers, who first backed rebel groups against Assad then shifted their focus to defeating the Islamic State jihadist group as part of a US-led coalition.
Assad lambasted the American and British interventions, saying they were "breaching the sovereignty of Syria".
"This is colonial policy, that's how we see it, and this is not new," he said.
He also told the Mail on Sunday that his country had stopped intelligence sharing with European nations.
"They want to exchange information despite their governments being politically against ours, so we said... When you change your political position, we're ready," he said.
"Now, there's no cooperation with any European intelligence agencies including the British."
The interview, according to the Mail on Sunday, was Assad's first with a British journalist since 2015. Its full transcript was published on Syrian state news agency SANA.