The White House says the United States will provide Ukraine with an additional $335 million in security assistance.
The new aid was announced Thursday after a meeting between U.S. Vice President Joe Biden and Ukrainian President Petro Poroshenko in Washington.
The White House also said that Biden told Poroshenko that efforts to form a stable, reform-oriented government were critical to unlocking international economic assistance, including a third $1 billion U.S. loan guarantee.
Last May, the U.S. signed a second $1 billion loan guarantee deal for Ukraine, to help it rebuild its economy after Russia annexed Crimea in 2014 and backed a separatist insurgency in the country's eastern Donbas region.
Washington has supported Ukraine's pro-Western government but also been concerned by pervasive corruption.
Ukraine's parliament sacked the country's chief prosecutor earlier this week over his alleged attempts not to pursue high-profile corruption cases.