The Syrian president also said he believes the Iranian nuclear deal will benefit Syria
Syrian President Bashar al-Assad expressed "strong confidence" on Tuesday that Russia will continue supporting his embattled government, speaking in an interview with Hezbollah's Al-Manar television network.
Assad also described as "legitimate" the presence in Syria of fighters from Hezbollah backing his forces.
The powerful Lebanese Shiite movement, along with Russia and Iran, have been Assad's major allies since Syria's revolt broke out in 2011.
"We have strong confidence in the Russians, as they have proven throughout this crisis, for four years, that they are sincere and transparent in their relationship with us," Assad said.
His rare television interview came as Russian President Vladimir Putin discussed the Syrian crisis with Jordan's King Abdullah II on the sidelines of the Maks-2015 aerospace show in Moscow.
Assad described Russia as "principled", while "the United States abandons its allies, abandons its friends".
He added: "This was never the case with Russia's policy, neither during the Soviet Union, nor during the time of Russia... Russia has never said that it supported President Such and Such and then decided to abandon him."
Assad had been asked by Al-Manar's correspondent about US President Barack Obama's comments earlier this month that Russia and Iran "recognise that the trend lines are not good for Assad".
He rebuffed the statement, saying Iran, too, remained a steadfast ally.
He said the recent nuclear deal between Iran and world powers would strengthen Iran's role internationally, in turn benefiting Syria.
"The power of Iran is the power of Syria, and a victory for Syria is a victory for Iran."
The president added: "We are on the same axis, the axis of resistance."
Syrian state is 'legitimate'
Officials in Washington and other Western nations have long called for Assad to go, insisting he could not play a role in a political solution to Syria's crisis.
Turning to the question of Hezbollah, he said "the difference (between Hezbollah and foreign anti-government fighters) is legitimacy. Who invited Hezbollah to Syria," Assad asked.
"It came after an agreement with the Syrian state, and the Syrian state is a legitimate state," whereas "the other terrorist forces came to kill the Syrian people".
Several international efforts to bring about a political solution to the four year crisis that has left more than 240,000 dead in Syria have failed.
Most recently, UN envoy to the Syrian crisis Staffan de Mistura launched a series of consultations in a step to rekindle talks between the government and political opposition.
But Assad accused de Mistura of making "biased statements," likely referring to the envoy's condemnation of government bombardment near Damascus that killed over 100 civilians on 16 August.
De Mistura's plan, set to begin in September, aims to set up four working groups to address safety and protection, counterterrorism, political and legal issues, and construction.
The plan received support from a UN Security Council presidential statement last week.
On Tuesday, Assad said any initiative must be based on "fighting terrorism".
"Any initiative that does not have combatting terrorism as a priority has no value," Assad said.
Throughout the four-year war, Syria's government has used the term "terrorist" to refer to peaceful activists, rebels, and militants alike.