They said: “What we can confirm is that, along with allies and partners, we are providing Ukraine with billions of dollars worth of security assistance, which our Ukrainian partners are using to extraordinary effect to defend their country against Russia’s unprovoked aggression and horrific acts of violence.”
It comes as the US is preparing to send another batch of military equipment worth $800m (£610m) bringing its military spend in Ukraine to $2.6bn since the start of the war in February.
The Biden administration has also made it clear that it will be sending increasingly heavy and sophisticated military equipment.
This includes helicopters, aerial and marine drones, and long-range 155mm howitzers.
Washington will also be ensuring that Ukrainian military personnel are fully trained in using the equipment.
The US has also agreed to send further anti-tank and anti-aircraft missiles that have made a major impact in the conflict so far.
Ukraine has claimed that it sank the Russian Black Sea Battleship Moskva on Thursday with Ukrainian-developed Neptune missiles.
The UK has also agreed to send more anti-ship missiles to help replenish Kyiv’s stockpiles.
The Czech Republic, however, has expressed its willingness to support Ukraine militarily, sending T-72 tanks and tracked armoured personnel carriers.