Putin is wanted under an arrest warrant from the International Criminal Court on charges of illegally deporting children from Ukraine.
When Russia's Vladimir Putin visits European Union and NATO member Hungary for a summit, it will be uncomfortable viewing for allies of Ukraine.
President said on Thursday he may meet his Russian counterpart in Budapest within two weeks, adopting a more conciliatory tone towards Russia.
The choice of Hungary for the summit raised eyebrows among diplomats and analysts.
Author's summary: Putin's Budapest visit sparks controversy.