US Defence Secretary Lloyd Austin on Monday promised to keep weapons flowing into Ukraine “week after week” as Kyiv struggles against a renewed Russian offensive.
Mr Austin also said it was vital that Ukraine's air defences be bolstered to help fend off Russian attacks.
Moscow has in recent weeks focused its attacks on north-east Ukraine, launching new assaults in the Kharkiv region.
Mr Austin and about 50 defence leaders from around the world met online on Monday to co-ordinate more military aid to Ukraine as it tries to hold off Russia's advances while conducting its own offensive in the occupied Crimean Peninsula.
“We're meeting in a moment of challenge,” he told colleagues.
He told reporters after the meeting: “We’ll continue to push to ensure that Ukraine owns its skies and can defend its citizens and its civilian infrastructure far from the front lines.”
The Ukrainian military has suffered setbacks in recent months, partly due to the US Congress delaying funding and equipment.
Ukraine has struggled to get enough troops to the front lines as the war drags on into its third year and fighting takes its toll.
In the four weeks since US President Joe Biden signed the $95 billion foreign aid package, which included about $61 billion for Ukraine, the US has sent $1.4 billion in weapons pulled from Pentagon stockpiles and announced it was providing $6 billion in funding through the Ukraine Security Assistance Initiative.
In recent packages, the US has agreed to send High Mobility Artillery Rocket Systems (Himars) and rockets for them, as well as munitions for Patriot and National Advanced Surface-to-Air Missile Systems, artillery, anti-aircraft and anti-tank munitions, and armoured vehicles, such as Bradley and Mine Resistant Ambush Protected vehicles.
The US has now provided about $50.6 billion in military assistance to Ukraine since Russia invaded in February 2022.
