The Obama administration said late Thursday that its patience with Russia has just about worn out, and that it’s close to giving up on the Syria peace process entirely unless Russia is prepared to take “extraordinary” efforts to end all military action in the war-torn country.

Senior State Department officials told reporters that the U.S. side is feeling “frustration” after a week that has seen Russia fail to work with Syria to end the conflict in order to begin political negotiations. The first humanitarian convoy that tried to reach victims of the civil war was bombed on Monday, and even as the U.S. and Russia were meeting later in the week, Syria continued to shell Aleppo.