LOS ANGELES (Reuters) - Director Christopher Nolan’s new thriller “Tenet” received warm reviews on Friday as U.S. cinema chains reopened with industry-wide safety measures aimed at reassuring audiences during a pandemic.

“Tenet” is the first big-budget movie from a major Hollywood studio to head to theaters since the coronavirus outbreak shuttered theaters around the world in March.

Ticket sales for the film from AT&T Inc’s Warner Bros will be closely watched as a gauge of how many people will leave their homes to go to the movies. The film opens in 70 countries starting on Aug. 26 and in the United States on Sept. 3.

“Tenet” got an 87% approval rate on review aggregator website Rotten Tomatoes, although critics said its time-bending plot was so contorted, it was hard to follow at times.

Star John David Washington plays a CIA operative recruited to help the shadowy Tenet organization that is trying to stop an apocalyptic event.

The Times of London called the 2.5-hour film a “globetrotting, jaw-dropping and delightfully convoluted big-screen blockbuster” and added “Cinema, finally, has returned.”

The New York Times said the movie was enjoyable and “reassuringly massive in every way as a piece of movie-making shot across multiple global locations.”

IndieWire was less impressed, calling the movie a “humorless disappointment.”

The Hollywood Reporter said “Tenet” has a lot riding on it. “There will be viewers scrutinizing every tweet, review and opinion aggregator as they weigh whether to leave their quarantine bubbles to see it,” it said.

Theaters have been gradually opening around the world. In the United States, major chains including AMC Theatres and Cineworld Plc’s Regal Cinemas opened their doors for this weekend with limited attendance, mask requirements and other measures to reduce the chances of catching the disease.

The National Association of Theatre Owners announced on Friday that operators of more than 30,000 screens had agreed a standard set of procedures.

“Moviegoers need to know that there is a consistent, science and experience-based set of health and safety protocols in place no matter what theater they visit,” said John Fithian, president of the industry group.

Reporting by Lisa Richwine and Jill Serjeant; Editing by Marguerita Choy