MOSCOW (AP) — Russian President Vladimir Putin and Ukrainian counterpart Volodymyr Zelenskiy spoke on the phone in advance of their first meeting next month.

Statements from the Kremlin and Zelenskiy’s office said the Monday call included discussion of negotiations between Russia, Ukraine and the European Union for Russia to keep sending gas to European customers in pipelines that cross Ukraine. A 2009 dispute left many European countries with gas shortages in mid-winter.

Zelenskiy’s office also said he insisted that Russia return documents from three Ukrainian naval ships that were seized by Russia in 2018 and returned to Ukraine last week.

Neither statement mentioned the planned Dec. 9 meeting in Paris with the leaders of France and Germany. The meeting is aimed at resolving the conflict between Ukrainian forces and Russia-backed separatist rebels.