The Michigan Hospital Association is warning of strained health systems as COVID-19 surges across the state.

Michigan is fast approaching its highest number of COVID-19 hospitalizations since the pandemic began, with more than 3,900 patients currently receiving care, according to state data. The vast majority of patients in the ICU and on ventilators are unvaccinated.

"Most hospitals throughout the state have more patients in their emergency departments than they do available rooms and staff to care for them," officials wrote in a statement on Monday. "This results in long wait times, patients being placed in hallways or conference rooms, and diverting patients away from a hospital because there is no physical room or medical staff available to accept more patients."

"We are extremely concerned because our best predictions are that COVID-19 patients will continue to increase during the weeks ahead as we enter the yearly flu season," they said.

-ABC News' Arielle Mitropoulos

The U.S. has reported an increase in pediatric COVID-19 cases for the third week in a row.

Nearly 142,000 children tested positive in the last week, which is a 16% increase from the week prior and a 41% jump over the last three weeks, according to a new report from the American Academy of Pediatrics and the Children’s Hospital Association.

Nearly 6.8 million children have tested positive for COVID-19 since the pandemic began.

COVID-19 cases among children remain "extremely high," the organizations said, and there have been almost 1.7 million additional cases since the first week of September.

The Midwest continues to see the highest number of pediatric cases.

Severe illness due to COVID-19 remains "uncommon" among children, AAP and CHA said. However, AAP and CHA continue to warn that there is an urgent need to collect more data on the long-term consequences of the pandemic on children, "including ways the virus may harm the long-term physical health of infected children, as well as its emotional and mental health effects."

-ABC News' Arielle Mitropoulos

Daily COVID-19-related hospital admissions are on the rise in the U.S., up 8.4% in the last week, according to federal data.

Nineteen states reported at least a 10% jump in hospital admissions over the last week: Georgia, Hawaii, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Jersey, New York, Ohio, Pennsylvania and Wisconsin.

Michigan, which is now reporting more cases than at any other point in the pandemic, has the nation's highest infection rate, followed by Minnesota, New Mexico, New Hampshire, North Dakota, Wisconsin and Maine.

Puerto Rico, Florida and Hawaii have the nation's lowest infection rates, according to federal data.

-ABC News' Arielle Mitropoulos

About 93% of TSA employees are in compliance with Monday's deadline for the federal employee vaccine mandate, TSA spokesperson Lisa Farbstein said.

"In compliance" means employees have had at least one shot or have filed for a medical or religious exemption.

Holiday travel won't be impacted by the mandate, Farbstein said.

-ABC News' Gio Benitez, Anne Flaherty