New York City entered phase two of reopening on Monday, marking a major milestone of the city's fight against COVID-19.

The transitioning is "a giant step for this city" with the largest chunk of New York's economy reopening in phase two, as Mayor Bill de Blasio said, including barbershops, hair salons, real estate, vehicle sales and rentals. Office work can resume, and people can once again browse in stores, except malls.

Playgrounds across the city are allowed to reopen, and thousands of restaurants can set tables in outdoor spaces such as in front of their establishment, sidewalk or curb space, with at least six feet between each table.

"Today is a very, very important day for this city," said de Blasio at a press briefing on Monday. "As the nation's largest city, the nation's largest economy gets back on its feet."

Some 150,000 to 300,000 people are expected to return to work, on top of the 200,000 to 400,000 people already back to work in phase one since June 8, according to the mayor.

Social distancing and face coverings are mandated in reopened businesses. The mayor said that another 2 million masks will be given out for free for small businesses to help them move forward.

The mayor said that the city's subway ridership was up 29 percent compared with right before phase one, approaching to a million, while bus ridership was up 22 percent in the same period.

Before the pandemic, an average of 5.5 million people took the subway on workdays.

Once the epicenter of the COVID-19 outbreak in the United States, the city has reported 209,562 cases and 22,321 fatalities, including 4,685 probable deaths, according to city data.

The transmission rate of COVID-19 in the city dropped to 1.1 percent on Sunday, a little above the state's rate of 0.97 percent, according to state data.

Meanwhile, daily COVID-19 fatalities in New York state dropped to 10, and total hospitalizations are 1,122, both at the lowest level since March, state data showed.