The Pentagon announced a new $150 million package of military assistance for Ukraine on Friday, just days before the Geneva summit between US President Joe Biden and Russian leader Vladimir Putin.
The military aid, which includes radar systems, drones and secure communications equipment, is in addition to $125 million in assistance announced in March, Pentagon spokesman John Kirby said.
With the second installment, the Biden administration has released all of the security assistance funds appropriated for Ukraine by Congress in the fiscal 2021 budget, the Pentagon said in a statement.
Kirby said the assistance is designed to "help Ukraine's forces preserve their country's territorial integrity (and) improve interoperability with NATO."
"The department continues to encourage Ukraine to enact reforms that are in line with NATO principles and standards to advance its Euro Atlantic aspirations," he said.
The European Union and NATO have backed Ukraine since Russia's annexation of Crimea and the outbreak of fighting between Ukrainian government forces and pro-Russian separatists in eastern Ukraine in 2014.
At the same time, they have pressed Kiev to enact political and economic reforms.
Tensions remain high in eastern Ukraine where pro-Russian separatists accused Ukraine on Friday of killing five fighters.
Kiev said it lost one soldier in shelling.
Biden and Putin are to meet in Geneva on Wednesday and Ukraine is expected to be a topic of discussion at their first summit.