The Biden administration announced on Monday that it send an additional $1 billion in security assistance to Ukraine as the war with Russia continues into its sixth month.

Why it matters: The aid comes several weeks after it was revealed the Kremlin has plans to annex large swaths of southern and eastern Ukraine.

• The fight for Ukraine's eastern Donbas, comprised of the Luhansk and Donetsk regions, marks a second phase of the war. Russia claimed control of Luhansk last month but fighting continues in full force in Donetsk.
• The package comes on top of another $550 million in military aid to Ukraine announced earlier this month.

The big picture: The new package will include new shipments of ammunition, equipment and weapons as well as medical supplies, acting Pentagon press secretary Todd Breasseale outlined in a Department of Defense press release.

• It will include more artillery and mortar ammunitions, as well as ammunition for High Mobility Artillery Rocket Systems (HIMARS), a mobile rocket launcher.
• Additional munitions for National Advanced Surface-to-Air Missile Systems (NASAMS), which can strike targets more than 100 miles away, will also be included.
• Also included are 50 armored medical treatment vehicles, hundreds of AT4 anti-armor systems, and 1,000 javelin missiles.

State of play: Since the start of the Biden administration, the U.S. has committed about $9.1 billion in security assistance to Ukraine since the war began, Colin Kahl, the undersecretary of defense for policy, said at a press briefing on Monday.

• Kahl observed that fighting has been intense in eastern Ukraine and intensifying in the south, but that Ukrainian morale and will-to-fight is "much higher" than on the Russian side.
• Russia has suffered between roughly 70,000-80,000 casualties, including killed and wounded, over the course of the war, Kahl said.
• Kahl added the figure was "pretty remarkable considering that the Russians have achieved none of Vladimir Putin's objectives at the beginning of the war."

What they're saying: "At every stage of this conflict, we have been focused on getting the Ukrainians what they need, depending on the evolving conditions on the battlefield," Kahl said.

• "We are working around the clock to fulfill Ukraine's priority security assistance requests, delivering weapons from the United States stocks when they are available and facilitating the delivery of weapons by allies," he added.