WASHINGTON, Oct 25 (Reuters) - Ukraine's external financing needs will be around $3 billion a month through 2023 in a best case scenario, but could rise as high as $5 billion if Russian bombing becomes "even more dramatic," IMF Managing Director Kristalina Georgieva said.

The International Monetary Fund is working with Ukrainian authorities to help define and implement its macroeconomic policies and what will be required to become a member of the European Union, as well as reliable financial gap projections, she told a conference in Berlin on Tuesday.

She said the IMF was also working toward a full-fledged IMF lending programme for Ukraine.

(Reporting by Andrea Shalal; Editing by Andrew Heavens)