The US recently agreed to provide Ukraine with anti-tank and other weapons.
Previously the Obama administration refused to provide weapons to Ukraine. This lack of support was despite assurances given to Ukraine in 1994. At the insistence of the two strongest powers in the world — Russia and the United States — Ukraine agreed to give up their 2000 nuclear weapons in exchange for perpetual guarantees of sovereignty and territorial integrity.
The War in Donbass is an armed conflict in the Donbass region of Ukraine. From the beginning of March 2014, protests by pro-Russian and anti-government groups took place in the Donetsk and Luhansk oblasts of Ukraine, together commonly called the "Donbass", in the aftermath of the 2014 Ukrainian revolution and the Euromaidan movement. These demonstrations, which followed the annexation of Crimea by the Russian Federation (February to March 2014), and which were part of a wider group of concurrent pro-Russian protests across southern and eastern Ukraine, escalated into an armed conflict between the separatist forces of the self-declared Donetsk and Luhansk People's Republics (DPR and LPR respectively), and the Ukrainian government. In the Donetsk People's Republic, from May 2014 until a change of the top leadership in August 2014, some of the top leaders were Russian citizens. During the middle of 2014, Russian paramilitaries were reported to make up between 15% and 80% of the combatants. There were an estimated 6,000 Russian troops and 40,000 rebels in the Donetsk and Luhansk regions of Ukraine as of September 2017.