French President Emmanuel Macron said on Monday the Syrian regime leader Bashar al-Assad remaining in power would be a “grotesque error”, citing his history in "creating thousands of refugees" and "massacring his own people". "We can see those who would like to return to normal as soon as the war against ISIS is finished: Bashar al-Assad would stay in power, the refugees... will return and Europe and few others would help with reconstruction," Macron said. But "such a scenario would be a grotesque error", he added. After coming to power in May last year, Macron shifted French policy towards prioritizing the destruction of ISIS rather than ousting Assad, warning of a "failed state" if the leader were forcibly removed. But he has previously called the Syrian regime leader an "enemy of the Syrian people" who should ultimately face a war crimes court. Macrons latest comments during a major foreign policy address to French ambassadors appeared to be a rebuke to Russian President Vladimir Putin, who is Assads biggest backer. On August 18, Putin called on Europe to financially contribute to the reconstruction of Syria to allow millions of refugees to return home. After more than seven years of brutal war, Macron warned in Mondays speech that Assad was on the verge of creating a fresh humanitarian crisis in Idlib province. The regime says it is determined to retake the northwestern province on the Turkish border -- Syrias last major rebel stronghold -- amid speculation of a looming Russian-backed assault. "The situation is alarming because the regime is threatening to create another humanitarian crisis in Idlib province and until now has shown no desire to negotiate the slightest political transition," Macron said. "This means reinforcing pressure on the regime and its allies, and I expect Russia and Turkey to take account of their roles and the commitments they have made," he added. "Since day one I have considered ISIS to be our principal enemy, and I have never made the ousting of Bashar al-Assad a condition of our diplomatic or humanitarian action in Syria," he said.