In September 2018, Hartzell was appointed EU Ambassador to Georgia, succeeding the Hungarian diplomat Janos Herman in this position.[2] In December 2019 he initiated a political dialogue between all the major political parties, which resulted in a cross-party agreement on 8 March 2020. Following contested parliamentary elections in September 2020, Ambassador Hartzell was again called on to facilitate a political agreement between the political parties, which he carried out together with his US counterpart, Ambassador Kelly Degnan. Following an intervention by European Council President Charles Michel, Ambassador Hartzell participated to EU-led mediation efforts that resulted in the agreement “A Way Ahead For Georgia” on 19 April 2021.[3] Following the decision taken by the ruling Georgian Dream party to leave the agreement, and after Georgia, in contrast to fellow former Soviet Union republics, Ukraine and Moldova, was not granted a EU candidate status in June 2022, Hartzell said Georgia could have been "better prepared" for its membership bid, "as it comes at a time when the EU is increasingly concerned about the country's current trajectory," hinting to the concerns over democratic backsliding under the Georgian Dream government.[4] In response, the Georgian Dream party chairman Irakli Kobakhidze denounced Hartzell as having "played a strictly negative role in relations between the European Union and Georgia" in July 2022, being promptly rebuked by the EU's Lead Spokesperson for External Affairs Peter Stano who made a statement in support of Hartzell.[5] Ambassador Hartzell's tenure in Georgia expired in August 2022, when he was succeeded by the Polish diplomat Pawel Herczyński.[6]