US Chairman of the Joint Chiefs Marine Corps Gen. Joseph Dunford said Saturday he was involved in “routine dialogue” with President Donald Trump about military options should the Syrian regime ignore warnings against using chemical weapons in an expected assault on the northwestern province of Idlib. “No decision had been made by the United States to employ military force in response to a future chemical attack in Syria,” Dunford stressed. “But we are in a dialogue, a routine dialogue, with the President to make sure he knows where we are with regard to planning in the event that chemical weapons are used,” he told a small group of reporters during a trip to India. “He expects us to have military options and we have provided updates to him on the development of those military options,” he added. Regime leader Bashar al-Assad has massed his and allied forces on the front lines in the northwest, and Russian planes have joined his bombardment of opposition factions there, in a prelude to a widely expected assault despite objections from Turkey. Last week, a top US envoy said there was “lots of evidence” that chemical weapons were being prepared by regime forces in Idlib. The White House has warned that the United States and its allies would respond “swiftly and vigorously” if the regime used chemical weapons in Idlib. Trump has twice bombed Syria over its use of chemical weapons, in April 2017 and April 2018. France’s top military official also said last week his forces were prepared to carry out strikes on Syrian targets if chemical weapons were used in Idlib. Dunford declined to comment on US intelligence about the possible Syrian preparations of chemical elements. Asked whether there was still a chance the assault on Idlib could be averted, Dunford said: “I don’t know if there’s anything that can stop it.” “It’s certainly disappointing but perhaps not (surprising) that the Russians, the Turks and the Iranians weren’t able to come up with a solution on Friday,” he said. He warned about the potential for a humanitarian catastrophe in Idlib and instead has recommended more narrowly tailored operations against militants there. “There’s a more effective way to do counter-terrorism operations than major conventional operations in Idlib,” he said. The presidents of Russia, Turkey and Iran had met in Tehran on Friday to strike a deal on Idlib and avert a military assault, but they failed in reaching an agreement.