President Joe Biden instructed the U.S. State Department to release $350 million in military aid to Ukraine on Friday as it struggles to repulse a Russian invasion.
In a memorandum to Secretary of State Antony Blinken, Biden directed that $350 million allocated through the Foreign Assistance Act be designated for Ukraine's defense.
A host of other countries are also providing military support.
France has decided to send defensive military equipment to Ukraine, a French army spokesman said on Saturday, adding that the issue of sending offensive arms was still under consideration.
"You can imagine that shipping the equipment is complicated at the moment", a spokesman for the French army's Chief of Staff told reporters at a briefing.
Slovakia will send military material worth 2.6 million euros ($2.9 million) and other aid worth 8.4 million euros to Ukraine, local media reported on Saturday.
Meanwhile, Estonia is sending Javelin anti-tank missiles and anti-aircraft munitions to Ukraine, public broadcaster ERR quoted the defence ministry as saying on Friday.
"We are providing ...25,000 packages of dry food, medical equipment, personal equipment, ammunition, additional Javelin missiles and anti-aircraft munitions," it quoted the ministry's Secretary General Kusti Salm as saying.
The Netherlands also plans to send military equipment to Ukraine, including rifles, ammunition, radar systems and mine-detecting robots, the government said on Friday.
"We continue to aim for a diplomatic solution", Foreign minister Wopke Hoekstra said. "But at the same time Ukraine must be able to defend itself against a possible Russian attack."
The Czech government also approved on Saturday sending weapons and ammunition worth 188 million crowns ($8.57 million) to help Ukraine defend itself against Russia's attack, the Czech Defence Ministry said.
The shipment, which includes machine guns, assault rifles and other light weapons, will be delivered by the Czech side to a location picked by Ukraine, the ministry said.
Last week, Ukraine had received a plane load of machine guns, surveillance gear and rifles as part of a Canadian military assistance package, Ukrainian Defence Minister Oleksii Reznikov said.
Ukraine received plane loads of arms and military gear from NATO allies as the country braced for the military attack by Russia.
"We received military aid in the form of rifles, machine guns with optical sights, night vision & surveillance devices & military equipment. Thank you for this important & timely decision," Reznikov wrote in a tweet.