The NCAA has canceled its March Madness basketball tournaments — and "all remaining winter and spring" championships — as coronavirus fears upend the sports world.

"This decision is based on the evolving COVID-19 public health threat, our ability to ensure the events do not contribute to spread of the pandemic, and the impracticality of hosting such events at any time during this academic year given ongoing decisions by other entities," the college athletics organization said in a statement.

CBS Sports and Turner Sports, which were set to broadcast the tournament, said in a joint statement that they are "fully supportive of the NCAA's decision to cancel this year's NCAA Division I Men's Basketball Championship. We'll continue to work closely with the NCAA and all of our partners as we prioritize the health and well-being of everyone involved."

Earlier Thursday, major conferences canceled their championship tournaments and sports organizations across the world rolled out fan restrictions and suspensions of play in light of the COVID-19 pandemic.

The Southeastern Conference, Big Ten Conference, Pac-12 Conference, Big East, Big 12 Conference and Atlantic Coast Conference all canceled their men's championship basketball tournaments ahead of the NCAA's announcement. At least two high-profile teams also individually announced their withdrawals from the tournament.

The NCAA had previously said the upcoming men's and women's March Madness basketball tournaments, which were scheduled to begin in days, would be played without fans. The conference tournament cancellations and global sports suspensions appear to have tipped the scales.

The COVID-19 pandemic is upending sports worldwide amid concern that large public events will increase the likelihood of transmitting the virus. There are currently more than 1,300 confirmed cases of COVID-19 in the United States and at least 38 deaths. There are more than 127,000 cases worldwide and at least 4,718 deaths attributed to the virus.

The ACC, in canceling its tournament, cited the "fluidity of COVID-19."

ACC statement on canceling conference tournament.

Duke University, in addition to pulling out of March Madness, suspended all athletic competition, including practices, indefinitely.

"During this unpredictable time, Duke Athletics fully supports all measures to protect the health and welfare of the Duke family and beyond," said Kevin White, Duke vice president and director of athletics, who chairs the NCAA Division I Men's Basketball Committee.

The Big 12 canceled its men's and women's basketball tournaments and immediately suspended all conference championships until April 15, at which time the Big 12 will assess the future of other championships this season, according to a statement.

Kansas, which plays in the Big 12, suspended all home and away athletic events and canceled all athletic travel indefinitely. The Jayhawks are the top-ranked men's basketball team in The Associated Press Top 25 poll.

The Big Ten and the SEC halted the remainder of their conference tournaments earlier Thursday.

The SEC's suspension of regular-season competition for all sports, as well as conference championship events, will remain until March 30, according to a statement.

The Pac-12 halted the remainder of its men's basketball tournament and canceled all Pac-12 sports competitions and conference championship events indefinitely.

Pac-12 cancellation statement.

The Big East conference men's basketball tournament had already begun at Madison Square Garden in New York City, but now will not continue. New York City Mayor Bill De Blasio declared a state of emergency on Thursday and warned that large-event venues like MSG could remain closed "for months."

The NCAA cancellations come on the same day Major League Soccer suspended its season for 30 days and a day after the National Basketball Association suspended the remainder of its season indefinitely after a Utah Jazz player tested positive for the illness.

— CNBC's Jessica Golden and Spencer Kimball contributed to this report.