NEW YORK (AP) — New York City will send sheriff’s deputies to the homes or hotel rooms of all travelers coming from the United Kingdom to ensure they comply with the city’s two-week COVID-19 quarantine requirement, Mayor Bill de Blasio said Wednesday.

De Blasio announced the enforcement action amid concern about a new, fast-spreading strain of the virus detected in the U.K. Airlines flying from London to New York agreed this week to test passengers before they board.

All travelers to New York, regardless of where they’re arriving from, are required to fill out forms with contact information and where they’ll be staying. They will then be sent a quarantine order by certified mail, de Blasio said.

People who fail to comply will face a fine of $1,000 per day, de Blasio said.

“We cannot take chances with anyone who travels, particularly folks traveling in from the U.K.,” de Blasio said.

“We don’t want to penalize people. Everyone’s been through hell this year,” he added. “We don’t want to, but if you don’t follow quarantine you’re endangering everyone else in the city, right as we’re fighting the second wave.”

Sheriff’s deputies have been key to New York City’s quarantine and social distancing enforcement, busting up large gatherings, shutting down noncompliant restaurants and bars and stopping cars traveling from out of state.

Sheriff Joseph Fucito said deputies visiting travelers from the U.K. will not only be enforcing compliance, but also telling them about city services available to help them through quarantine. The mayor’s office, for example, can help with housing and food, Fucito said.