An advocacy group for deaf Americans is suing the White House for failing to provide real-time sign language interpretation during COVID-19 news briefings, saying the omission violates the First Amendment and laws for Americans with disabilities.

The National Association of the Deaf says in a federal lawsuit filed Monday that President Donald Trump and his White House coronavirus task force briefings have not featured an American Sign Language interpreter visible on-screen, known as televised in frame ASL interpretation, since the briefings began in March.

By failing to provide an interpreter, the administration is blocking access to critical, potentially life-saving information conveyed by our nations political and public health leaders during the COVID-19 pandemic, the lawsuit contends.

Closed captioning, required by federal law , is not a sufficient alternative because it is prone to error and can be hard to follow in real time, especially for people whose first language is not English, the suit says.

In addition, as the lawsuit explains, tone is also often lost in written captions. By contrast, an interpreter is able to convey tone and context of a message through facial expressions, sign choice, and demeanor.

The group says the governors of all 50 states and mayors of many major cities have provided on-screen ASL interpreters during their COVID-19 briefings. More than 3.4 million Americans identify as deaf, and about 17 million report having serious difficulty hearing, according to a 2014 census survey of Americans with disabilities .

Several governors faced lawsuits for initially failing to consistently provide on-screen sign language interpreters during their televised coronavirus updates. Deaf New Yorkers and disability rights advocates sued Gov. Andrew Cuomo (D) for not having an on-screen ASL interpreter at his widely viewed news briefings in April, when New York was the epicenter of the pandemic in the U.S. A judge ordered Cuomo to do so two weeks later, and he has provided one in his briefings since.