The United States has provided $65.9bn in military support to Ukraine since Russia's invasion in February 2022 but further contributions hang in the balance after US President Donald Trump ordered a pause on aid to Kyiv.
Then-president Joe Biden approved the assistance, reaffirming what the US State Department called America's "unwavering support for Ukraine's sovereignty and territorial integrity".
That changed with Mr Trump's shock shift in approach to the war.
Here is a review of the main deliveries of military aid to Ukraine, according to a list provided by the State Department on 20 January.
Air defence
Given the relentless barrages of air attacks from Russian forces, Washington sent Kyiv increasingly sophisticated air defence material, including three Patriot surface-to-air missile batteries. European allies also provided such systems to Ukraine.
Other defence systems on the list included 12 NASAMS as well as HAWK systems and munitions, and more than 3,000 Stinger anti-aircraft missiles.
To improve their effectiveness, 21 air surveillance radars were provided, along with equipment that integrated western launchers and missiles to Ukraine's systems.
Missiles, mortars
Washington sent more than 200 155mm howitzers along with three million corresponding artillery rounds, 72 105mm howitzers and a million rounds, and upwards of 700,000 mortars.
More than 40 HIMARS, rocket launchers mounted on light armoured vehicles, were delivered with the corresponding ammunition.
Washington also gave Ukraine more than 10,000 Javelins, anti-tank missiles that became symbols of Ukrainian resistance against the Russian invasion in the first weeks of the war.
Over 120,000 other anti-vehicle weapons were delivered, as well as 10,000 TOW anti-tank missiles.
For smaller weapons, more than 500 million rounds of small arms ammunition and grenades were supplied to Ukrainian soldiers.
Tanks, choppers
While the Pentagon has so far refused to send its combat aircraft directly to Kyiv, the Biden administration did provide 20 Soviet-designed Mi-17 military helicopters. It also delivered several different models of drones.
And after lengthy Biden administration delays, Washington delivered a total of 31 Abrams, the most advanced US heavy tanks, beginning in January 2023. Some 45 Soviet-designed T-72B tanks were also sent.
The State Department list also included 300 Bradley fighting vehicles, 1,300 armoured personnel carriers, more than 5,000 Humvee military vehicles and 300 armoured ambulances.
Washington provided more than 100 patrol boats, coastal defence systems, Claymore mines, satellite communication systems, night vision goggles and more than 100,000 sets of body armour.
After 20 January
The above figures date from 20 January, in the final hours of the Biden administration.
Since Mr Trump took office later that day, Washington has continued to deliver to Ukraine what a US defence official called "critical munitions" approved by the previous administration, including anti-tank weapons and artillery rounds.
