NEW YORK, Jan. 25 (Xinhua) -- New York City's COVID-19 test positivity rate on a seven-day average went down to 8.44 percent, compared with 8.82 percent one day earlier, Mayor Bill de Blasio tweeted on Monday.

Meanwhile, de Blasio said that there were 240 new hospital admissions and new cases of the coronavirus reached 4,743. "We need to KEEP fighting while we're waiting for more vaccines so we can turn this situation around."

At his daily news briefing on Monday, de Blasio said that the city was postponing the opening of COVID-19 mass vaccination sites at Yankee Stadium, Citi Field and Empire Outlets in Staten Island due to a lack of supply.

To date, the city had vaccinated 628,831 people, and it was expecting a supply of 107,825 doses of the vaccine this week, not enough to open the major sites, he said.

"We urgently need more supply," the mayor said, adding that the city had the capacity to vaccinate 500,000 individuals each week once it had sufficient supply.

The city currently has 19,032 first doses remaining in stock. To open the mass vaccination sites, the city needs about 200,000 doses in stock.

As of Sunday evening, coronavirus deaths added up to 26,558 and confirmed cases 560,726 in NYC, according to The City, a project that tracks the spread of confirmed COVID-19 infections and fatalities in New York City, based on information provided by the New York City Department of Health and Mental Hygiene, the governor's office, The COVID Tracking Project and the Center for Systems Science and Engineering at Johns Hopkins University.