Humanitarian assistance to Syria was among the issues President Joe Biden said he discussed with Russian President Vladimir Putin during their highly anticipated summit on Wednesday, as pressure builds on Moscow to greenlight a cross-border aid operation described as a lifeline for millions of Syrians.

The two leaders addressed “the urgent need to preserve and reopen the humanitarian corridors in Syria,” Biden said during a press conference in Geneva that followed his first face-to-face meeting with his Russian counterpart since taking office.

A UN Security Council resolution that keeps humanitarian aid flowing from Turkey to the northwestern Syrian province of Idlib is set to expire on July 10. Relief agencies have warned that a failure to renew the UN’s cross-border aid operation would jeopardize food assistance for more than 1 million people and limit what COVID-19 supplies and life-saving medicine reach war-ravaged Idlib.

The United States is calling on the 15-member council, in particular Russia, to vote to reauthorize the Bab al-Hawa crossing on the Turkish border and renew two other shuttered access points that supplied the rebel-held northwest and Kurdish-controlled northeast before Russian obstruction forced them to close last year.