U.S. Pledges $1 Billion In More Rockets, Other Arms For Ukraine

The US Department of Defense is sending ammunition, rockets, and other arms to Ukrainian troops as Russia moves its forces towards southern port cities. Military commanders emphasize the importance of high-tech weaponry for Ukraine's defense. Since the Russian invasion in February, the US has provided approximately $9 billion in aid to Ukraine.

What warning have analysts given regarding Russia's military movements?

What is the significance of the aid being sent to Ukraine?