The Donald Trump administration is scrambling to get concessions out of Russia on Syria before the Bashar al-Assad regime completes its reconquest of the country, greatly constraining any remaining US leverage.

With Assad’s forces poised to take back the last remaining rebel bastion of Idlib, US officials are in a race to get Moscow to help curtail Iranian influence. Washington is worried that a final Assad victory will give Tehran and its proxies free rein to ferry weapons and supplies through to the Mediterranean Sea, threatening Israel and other US allies.

Publicly, the administration has put the Assad regime on notice against using chemical weapons while relaying to Russia its concerns about a humanitarian catastrophe in Idlib. During a five-hour meeting in Geneva last week, US national security adviser John Bolton pressed his Russian counterpart Nikolay Patrushev on the issue, a National Security Council spokesman told Al-Monitor.

Even as the administration rolled out an expanded Syria team last week to get UN-led peace talks back on track, however, US officials appear increasingly resigned to a bloody battle for the city. A source close to the administration told Al-Monitor on condition of anonymity that the Trump team has already accepted that Assad’s forces are going after Idlib, and that the United States has little capacity — or desire — to stop them.