The US military plans on staying in Syria as long as necessary to ensure ISIS does not return, a Pentagon official told AFP. "We are going to maintain our commitment on the ground as long as we need to -- to support our partners and prevent the return of terrorist groups," Pentagon spokesman Eric Pahon said. The United States currently has approximately 2,000 troops on the ground in Syria, where they have been helping train and advise the Syrian Democratic Forces in the fight against ISIS. Pahon said the US troop commitment would be "conditions-based," meaning no timeline will determine any pull out. "To ensure an enduring defeat of ISIS, the coalition must ensure it cannot regenerate, reclaim lost ground or plot external attacks," he said.  "The United States will sustain a conditions-based military presence in Syria to combat the threat of a terrorist-led insurgency, prevent the resurgence of ISIS, and to stabilize liberated areas." Pahon stressed the US would maintain its support for the Kurdish-Arab alliance . Criticizing Russia, the spokesman said Moscow doesnt "appear to have a plan on how to bring a meaningful conclusion to the civil war that addresses the fundamental problems that led to the rise of ISIS, nor do they appear to be serious about the withdrawal of Iranian-backed militias,” including Lebanon’s Hezbollah, which Washington considers a terrorist organization.