He said this during the US Congress hearings, Ukrainian mass media reports.
"It is difficult (to predict how long it will be needed to support Ukraine - ed.), because we do not know the exact trajectory of the conflict's development. It may end in six months or in two-three years. President Biden says that we will support Ukraine as long as necessary," he said.
Kahl noted that Ukraine’s victory depends on the US and allies' help.
The United States announced a large-scale $2 billion defense aid package for Ukraine.