Washington will provide an additional $2.98 billion in weapons and equipment to Ukraine as the European country celebrates its national day, US President Joe Biden has said.
“Today is not only a celebration of the past, but a resounding affirmation that Ukraine proudly remains — and will remain — a sovereign and independent nation,” Mr Biden said on Wednesday.
The US has provided $13.6bn in military aid to Ukraine so far.
The White House said the latest tranche of aid would be provided through the Ukraine Security Assistance Initiative, a programme approved by Congress that allows the Biden administration to procure weapons from industry, rather than taking them from existing defence stocks.
Included in the package are hand-launched Puma drones, equipment for long-endurance ScanEagle surveillance drones launched by catapult as well as the Vampire anti-drone system, which can be launched off of ships.
The package also provides funding for six surface-to-air missile systems as well as munitions for them, 24 counter-artillery radars, more than 300,000 rounds of artillery and mortar ammunition and a "substantial package" for training, maintenance and sustainment of these systems.
Wednesday's $3bn package is "not relevant to the fight today, tomorrow, next week. It is relevant to the ability of Ukraine to defend itself and deter further aggression, a year from now, two years," Colin Kahl, under secretary of defence for policy, said during a news briefing at the Pentagon.
In addition, the package is meant to reassure Ukrainian officials of America's long-term commitment to supporting the country as it continues to fight Russia.
Ukraine's independence day was a bittersweet occasion for many, as it coincided with the six-month mark of a brutal Russian invasion that has killed 5,800 civilians so far, including 972 children, the United Nations says.
“Six months of relentless attacks have only strengthened Ukrainians’ pride in themselves, in their country and in their 31 years of independence,” Mr Biden said.
“Today and every day, we stand with the Ukrainian people to proclaim that the darkness that drives autocracy is no match for the flame of liberty that lights the souls of free people everywhere.”
Officials in the US capital joined the president in marking the occasion and condemning Russian President Vladimir Putin's war-waging.
"President [Volodymyr] Zelenskyy and the Ukrainian people have inspired the world with their courage and patriotism in the face of Vladimir Putin’s violent, unlawful aggression towards their country, especially in the past six months," said Rep Adam Smith, chairman of the House Armed Services Committee, in a statement on Wednesday.
"I witnessed this resilience first-hand during my visit to Kyiv just last month and I have been proud to support legislation that aids the Ukrainian people in their brave struggle for independence, sovereignty and freedom."
In keeping with the solidarity between Washington and Kyiv, Michael McCaul, Republican leader on the House Foreign Affairs Committee, said: "The significance of Ukraine’s 31st Independence Day cannot be understated. The US will never recognise any territory illegally occupied by the murderous Putin regime."
The latest batch of military support from the US could take months to arrive in Europe, given that companies have still to procure the arms, Reuters reported.
Defence Secretary Lloyd Austin shared photos on Twitter of US troops loading Ukraine-bound munition packages.
US defence leaders are also considering plans to expand training for Ukrainian armed forces on Europe’s eastern and southern flanks that are most prone to Russia’s aggression.
Additional reporting by Kyle Fitzgerald