The expansion, which involves the West Mashivske prospect, will increase Elizavetovskoye license area to 104.7km2.
JKX chief executive Dr Paul Davies said: "We have been forced to suspend drilling operations in Ukraine because of the current punitive levels of production tax and restrictive currency controls.
"Drilling on the West Mashivske prospect will also be deferred until investment conditions improve."
The Elizavetovskoye license, which is valid until 31 July 2034, is located in the central part of the Dnieper-Donets basin.
Covering 33.9km², the West Mashivske prospect will primarily focus on the Permian A8 sandstone reservoir, which is at a similar depth to the Permian A2 carbonate reservoir in the main Elizavetovskoye field.
The company said that the production will be tied back to the expanded Elizavetovskoye production facility.
JKX Oil & Gas has licenses in Ukraine, Russia, Hungary and Slovakia.
