Supplies of arms, ammunition and other security assistance sent by the United States to Ukraine as part of the latest $800 million aid package have already begun arriving in Ukraine, CNN reported, citing its own U.S. government sources.

"Shipments from the Biden administration's latest security assistance package to Ukraine 'have begun arriving', a White House official told CNN Saturday," the report says.

"President Biden this week approved an additional package of $800 million worth of weapons, ammunition, and security assistance to Ukraine," it says.

"The U.S. has, for the first time, agreed to provide Kyiv with the types of high-power capabilities some Biden administration officials a few short weeks ago viewed as too great of an escalation risk, including 11 Mi-17 helicopters; 18 155 mm Howitzer cannons and 300 more Switchblade drones," it reads.

"On Friday, a senior defense official told CNN the first flight of weapons and equipment was expected to arrive in the region in the following 24 hours and would be picked up at the border by Ukrainians and taken into the country," it says.

The Interfax-Ukraine agency has no confirmation of this information from official sources in Ukraine.