US Defense Secretary Jim Mattis said Thursday that the United States was committed to helping Ukraine's military, and sanctions against Russia would remain in place until Moscow stops supporting rebels and returns Crimea.
"Mr President, we continue to support Ukraine and remain committed to building the capacity of your armed forces," Mattis said after meeting Ukrainian President Petro Poroshenko.
He said Washington has recently approved delivery of military equipment worth $175 million (148 million euros) to Ukraine that would boost its defence capacities.
But the issue of lethal weapons is still under consideration, he added.
"On the defensive lethal weapons, we are actively reviewing it," he said.
"Defensive weapons are not provocative unless you are an aggressor. And surely Ukraine is not an aggressor."
"The United States stands with Ukraine," Mattis said, accusing Moscow of "seeking to redraw international borders by force, undermining the sovereign and free nations of Europe."
Sanctions against Russia "will remain in place until Moscow reverses the actions that triggered them," he said.
Kiev is battling a pro-Russian insurgency in the eastern regions of Lugansk and Donetsk.
Parts of these regions declared independence in 2014, shortly after Moscow seized the Black Sea Crimea peninsula from Ukraine.
More than 10,000 people have died in the conflict. Ukraine and the West accuse Russia of orchestrating and fuelling it with weapons and troops brought across the porous border.