Coronavirus updates: Herd immunity by fall 'ambitious,' says surgeon general nominee

In a continued encouraging sign, the number of people currently hospitalized with COVID-19 in the United States decreased on 13 days in January, according to The COVID Tracking Project, a volunteer-run effort to track the U.S. outbreak. 

That metric, which is "more resilient" than others to holiday reporting disruptions, increased six times this month, most recently on Jan. 12, The COVID Tracking Project said. 

There are 123,820 people currently hospitalized with COVID-19 nationwide. 

The U.S. also recorded 144,047 new cases of COVID-19 and 2,141 additional deaths from the disease on Tuesday, though national data was incomplete due to the holiday weekend, according to The COVID Tracking Project.

U.S. President-elect Joe Biden and Vice President-elect Kamala Harris honored the 400,000 Americans who have died from COVID-19 with a tribute in front of the Lincoln Memorial Reflecting Pool in Washington, D.C. on Tuesday evening.

The 400 lights along the pool were lit to symbolize the lives lost to the virus.

At the ceremony, part of the incoming administration's inaugural festivities, Harris called on Americans to "grieve and begin healing together."

"Though we may be physically separated, we, the American people, are united in spirit," she said.

Emirates Airlines and Etihad Airways said they have partnered with the International Air Transport Association to trial IATA Travel Pass -- a mobile app that serves as a “digital passport” to verify pre-travel COVID-19 testing or vaccination status.

The app also helps passengers find information on travel and entry requirements at their destinations.

Emirates Airlines said it plans to roll out the first phase in April, during which passengers leaving Dubai can share their COVID-19 test status directly with the airline through the app before arriving at the airport. Etihad will first offer the travel pass on some flights out of Abu Dhabi in the first quarter of 2021.

ABC News’ Christine Theodorou contributed to this report.

The United Kingdom reported a record 1,610 new fatalities from COVID-19 on Tuesday, bringing the country's weekly death toll to 8,267 -- a 19.8% increase over the previous week.

The U.K. -- an island nation of 66 million people made up of England, Scotland, Wales and Northern Ireland -- has the fifth-highest number of confirmed deaths from COVID-19 worldwide, behind the United States, Brazil, India and Mexico, according to a count kept by Johns Hopkins University.

Despite the record death toll, the daily number of new cases is on the decline in the U.K. amid national lockdowns. The U.K. reported 33,355 new cases on Tuesday, bringing the weekly total to 302,802 -- a 22.3% decrease from the last week.

ABC News’ Christine Theodorou contributed to this report.