The amount is part of a series of Pentagon payments now totaling $1.5 billion to the country since 2014, when Russia annexed the Crimean peninsula and a conflict erupted in eastern Ukraine.

"The United States remains committed to helping Ukraine ... to strengthen democratic civilian control of the military, promote command and control reforms, enhance transparency and accountability in acquisition and budgeting, and advance defense industry reforms," a Pentagon spokesman said.

"These reforms will bolster Ukraine's ability to defend its territorial integrity in support of a secure, prosperous, democratic, and free Ukraine."

Almost 13,000 people have been killed since the Moscow-backed insurgency broke out in April 2014 following Russia's annexation of Crimea.

Ukraine and its Western allies accuse Russia of funneling troops and arms to the pro-Moscow rebels across the border. Moscow denies the allegations.