President Biden is urging Americans to take precautions while celebrating the July 4 holiday this weekend.

Speaking to reporters on Friday, Biden voiced his concern that “people will die” after attending large gatherings in places where vaccination rates are low.

“I am concerned that people who have not gotten vaccinated have the capacity to catch the variant and spread the variant to other people who have not been vaccinated,” Biden said. “I am not concerned there is going to be a major outbreak; in other words, that we’re going to have another epidemic nationwide, but I am concerned lives will be lost.”

Biden urged those hesitant to get vaccinated to reconsider in the hope that next year’s celebrations could be even better.

“For those of you who haven’t been vaccinated because you don’t want to go through with it—it doesn’t hurt, it’s accessible and free, it’s available. And don’t only think about yourself, think about your family, think about those around you,” Biden said. “That’s what we should be thinking about so the Fourth of July this year is different to the Fourth of July last year. It’s going to be better next year.”

Biden fell short of his goal for 70 percent of U.S. adults being vaccinated by Independence Day. Federal data show 67 percent of adults have received at least one dose of the vaccine. 

His remarks arrive as the COVID-19 Delta variant continues spreading internationally. 

Earlier this week, WHO official Dr. Mariangela Simao advised fully vaccinated people to continue wearing masks. “People need to continue to use masks consistently, be in ventilated spaces, hand hygiene, avoid crowding,” Simao told CNBC. “This still continues to be extremely important, even if you’re vaccinated when you have a community transmission ongoing.”

According to WHO officials, the variant—which President Joe Biden has called a “serious concern”—has now been found in 92 countries as of Friday. It has also been detected in all 50 U.S. states. Dr. Mike Ryan, executive director of the WHO’s health emergencies program, said the variant could be “more lethal because it’s more efficient in the way it transmits between humans and it will eventually find those vulnerable individuals who will become severely ill, have to be hospitalized and potentially die.”