A debate is underway regarding how many and what kind of amphibious ships the U.S. Navy needs. These are the vessels U.S. Marines use both in combat operations and in noncombatant evacuations like getting Americans out of Sudan or providing humanitarian assistance after natural disasters. These two articles do a great job of explaining the issue.
"Evacuating Sudan: An Amphibious Gap and Missed Opportunity" - Defense News
"The Navy and Marine Corps have studied the question on the correct number of amphibious ships for several years now, and there seems to be consensus among those armed services that the correct number is 31 big-deck amphibious ships. The problem in getting to and sustaining that number does not reside inside the Navy or the Marine Corps, but rather with the Office of the Secretary of Defense, which does not embrace the value of the amphibious warship in 21st century warfare."
"Marines Want 31 Amphibious Ships. The Pentagon Disagrees. Now What?" - Defense News
"Today, the Navy has 31 amphibious ships — what the Marine Corps considers the bare minimum it needs — but the Pentagon plans to shrink the fleet below that number in fiscal 2024...Throughout last year and into this spring, that number — 31 — has been at the center of debates, as the Navy, Marine Corps, Defense Department, Congress and industry weigh in on how many amphibious ships the military needs, what they should look like and how much they should cost."