Ukrainian investigators have opened a criminal case involving Defence Minister Rustem Umerov, a move likely to deepen a standoff in his ministry over arms procurement that could strain Kyiv's ties with important Western allies.

Western officials have warned that a growing dispute between Ukraine’s defense minister and the head of its procurement agency could undermine trust and disrupt weapons supplies

Ukraine's government on Tuesday sacked a deputy defence minister in charge of weapons purchases amid infighting over procurement that is complicating Kyiv's attempt to reassure key Western partners at a critical moment in the war with Russia.

The conflict erupted last Friday, when Ukrainian defence minister Rustem Umerov sacked Maryna Bezrukova, director of the country’s defence procurement agency, over an “unsatisfactory” job performance and failure to deliver arms and ammunition to the troops on the frontline.