Washington officials are quoted as saying that equipment worth $75m is to be sent in the coming weeks, to help Ukrainian forces fight pro-Russian separatists.
The US is to send more non-lethal aid to Ukraine, including unarmed drones and Humvee military vehicles, according to Washington officials.
The White House confirmed that Vice-President Joe Biden had spoken to Petro Poroshenko, the Ukrainian President, and discussed non-lethal assistance.
According to the New York Times quoting the White House press secretary, the amount of new aid is worth 75 million dollars (71 million euros).
Other non-lethal equipment, such as anti-mortar radars and night vision goggles, has already been sent. The US has pledged assistance worth 118 million dollars (112 million euros) although only about half has been delivered, according to Washington officials.
The question of the US sending weapons to Ukraine remains on the table. Two congressmen wrote to Barack Obama this week calling on the president to submit an immediate report to Congress on plans for providing arms.
Last month President Poroshenko said he was confident the US and its allies would send weapons.
The US is also threatening more sanctions, a day after a congressional hearing heard claims that Russia has been flouting the Minsk ceasefire deal by sending more military hardware into eastern Ukraine.
“Just in the last few days, we can confirm new transfer of Russian tanks, armoured vehicles, heavy artillery and rocket equipment over the border to the separatists in eastern Ukraine,” US Secretary of State for Europe, Victoria Nuland, told the hearing on Tuesday (March 10).
The Kremlin has denied that its forces are directly involved in Ukraine, despite a catalogue of detailed claims to the contrary – from NATO, Western politicians, diplomats and defence officials, military experts, Russian journalists, Russian soldiers’ relatives, human rights groups, and other evidence.
Victoria Nuland also said Crimea and parts of eastern Ukraine had been suffering a “reign of terror”.
Moscow remains defiant over its annexation of the Black Sea peninsula a year ago.
A foreign ministry official said Russia had the right to deploy nuclear weapons in Crimea, although he knew of no plans to do so.
“I don’t know if there are nuclear weapons there now. I don’t know about any plans, but in principle Russia can do it,” said Mikhail Ulyanov, the head of the ministry’s department on arms control, was quoted as saying by Interfax news agency.
At a news conference on Tuesday, Russian Foreign Minister Sergei Lavrov defended the legality of Moscow’s stance towards Crimea, arguing that ethnic Russians there were under threat from the authorities in Kyiv and Ukrainian nationalists.