The Head of Ukraine’s Parliament’s Financial Committee says the government collected 101 billion hryvnias in taxes in May.
However, the committee said it had to spend more than double that on the war.
Danylo Hetmantsev says they spent 250 billion hryvnias financing the army and supporting people who had been forced to leave their homes, or whose homes had been destroyed.
The committee said Ukraine needs to borrow $5bn monthly or cut spending sharply.
It said the United States, the European Commission and some other countries had provided financial support.
However, the committee says the amount is far below the $5bn needed each month.