Tokyo raised its alert for medical preparedness to the highest level on Thursday for the first time, as hospital beds across Japan's bustling capital fill up with COVID-19 patients.

Following a coronavirus committee meeting, Tokyo officials raised the alert level to "red" and warned that the city's health care system was on the verge of crisis.

The move comes after 822 new cases of COVID-19 were confirmed in Tokyo on Wednesday, the highest single-day count the city has recorded since the start of the pandemic.

Wednesday's tally shatters Tokyo's previous record of 678 new cases confirmed a day earlier, according to data released by the Tokyo metropolitan government.

ABC News' Anthony Trotter contributed to this report.

Several European leaders announced Thursday that they are going into quarantine after French President Emmanuel Macron tested positive for COVID-19..

Portuguese Prime Minister Antonio Costa, who had lunch with Macron at the French presidential palace in Paris on Wednesday, said he is self-isolating as a preventative measure and canceling any events that require his physical presence. Costa said he also took a COVID-19 test on Thursday morning as was originally planned ahead of his now-canceled trip to Africa.

Spanish President Pedro Sanchez, who had lunch with Macron in Paris on Monday, said he will suspend all his activities and quarantine until Dec. 24

Belgian Prime Minister Alexander De Croo, who met with Macron in Brussels last week, said he will get tested Thursday and then self-isolate while he awaits the result.

ABC News' Ibtissem Guenfoud contributed to this report.

Some 885,000 workers in the United States filed for unemployment insurance last week, the U.S. Department of Labor said Thursday, as the pandemic continues to upend the labor market.

This is an uptick of 23,000 from the previous week’s figure.

More than 20 million people are still receiving some form of unemployment benefits through all programs as of the week ending Nov. 28, according to the Department of Labor. For the comparable week in 2019, that figure was 1.8 million.

The latest economic data comes as COVID-19 cases continue to climb across the country. The U.S. hit a record high on Wednesday of 247,403 newly confirmed cases of COVID-19 and 3,656 additional deaths from the disease.

The latest tally of weekly unemployment claims also comes as lawmakers have struggled to reach a deal on new relief. On Wednesday, after months of stalled negotiations, a source told ABC News that congressional leaders were close to a reaching a deal that could include enhanced federal unemployment benefits.

The national unemployment rate in the U.S. was 6.7% last month, according to the Department of Labor's most-recent jobs report. In February, prior to the coronavirus pandemic, the U.S. unemployment rate was 3.5%.

ABC News' Catherine Thorbecke contributed to this report.

Jennifer Mendoza, of Grapevine, Texas, gave birth to her fourth child in October.

A few days after coming home from the hospital with her healthy baby girl, Mendoza developed breathing problems.

Mendoza returned to the emergency room and subsequently tested positive for COVID-19. She never went home.

Mendoza died on Dec. 3, her 34th birthday, according to a report by Dallas ABC affiliate WFAA. She is survived by her husband and four young children.

"Her kids were everything," Mendoza's brother, David Mendoza, told WFAA in a recent interview. "To her last minute, she still kept fighting for them."

"I’m going to tell them every day for the rest of their lives that their mother was the most beautiful person on this earth," he added, "the most compassionate and the most big-hearted."