NEW YORK- New York City will put up COVID-19 quarantine checkpoints at key entry points to ensure that travelers from 35 states on New York state's travel advisory comply with the state's 14-day quarantine mandate, Mayor Bill de Blasio said on Wednesday.

"Travelers coming in from those states will be given information about the quarantine and will be reminded that it is required, not optional," de Blasio told a news briefing. He added that, under certain circumstances, fines for not observing the quarantine order could be as high as $10,000.

The Sheriff's Office, in coordination with other law enforcement agencies, will begin deploying checkpoints at major bridge and tunnel crossings into New York City on Wednesday.

"This is serious stuff and it's time for everyone to realize that if we're going to hold at this level of health and safety in this city, and get better, we have to deal with the fact that the quarantine must be applied consistently to anyone who's traveled," de Blasio said.

(Reporting by Maria Caspani in New York and Brendan O'Brien in Chicago; Writing by Lisa Shumaker; Editing by Howard Goller) ((Lisa.Shumaker@tr.com; +1 312-371-3983; @LisaLShumaker))