"Because this product presents such a serious fire hazard, I am urging all consumers ... to take advantage of this recall right away," said Elliot Kaye, chairman of the U.S. Consumer Product Safety Commission.
Samsung had already initiated a voluntary recall, but the company has been criticized for not offering clear information about the problem or how it would be resolved. While speaking with reporters, Kaye appeared to blast Samsung for not coordinating with his agency.
"As a general matter it's not a recipe for a successful recall for a company to go out on its own," he said, adding that anyone who believes a unilateral effort would be sufficient "needs to have more than their phone checked."
Samsung has said the problem involves about 2.5 million smartphones worldwide; authorities say that includes about 1 million in the United States. While the company was previously offering to replace the phones, it will now offer consumers the choice of a replacement or a full refund.
"I do like my phone," said Li Lei.
But even Lei, a loyal Samsung user, admits her Note 7 has problems.
"Sometimes it's really hot. The back of the phone, even though I have the phone case," said Lei.
Samsung has received 92 reports of batteries overheating in the U.S., and dozens of other reports of burns and property damage, including fires in cars and a garage.
Consumers should check their phones for a special code etched on the back. Then plug that number in on www.samsung.com. That will be key in determining if the phone you have is part of the recall.
This comes as new problems surfaced Thursday of other Samsung phones having similar problems. Video shows out of nowhere a Samsung phone overheat and explodes in a café.
Grace Clark says her phone gave her an issue only once.
"I did experience it getting hot one day, and I had up against my ear, and I thought it was going to explode, but I immediately shut it down," said Clark of Somerdale, New Jersey.
"I haven't had any problems with this one. I got it Fourth of July weekend, and I haven't had any problems with it. Even when I'm charging it, it doesn't get overheated," said Kyla Neil of North Philadelphia.
And for those who do chose to keep their recalled Note 7, the Feds are adamant, the phones must be shut off and disconnected from a charger before boarding a plane.
"It's a phone, it's a camera, it's a calculator, it's a computer, it's everything else you can hold in your hand. I think that's one of the problems - trying to put too much in such a small platform," said Michael Sabo of South Jersey.
For those who chose to get their Note 7 replaced, replacement phones will be available Sept. 21.
The timing of the recall couldn't be any worse since Apple debuts its iPhone 7 on Friday.
The recalled devices have a 5.7 inch screen and were sold in the following colors: black onyx, blue coral, gold platinum and silver titanium with a matching stylus. Samsung is printed on the top front of the phone and Galaxy Note7 is printed on the back of the phone.
They were sold at wireless carriers and electronic stores nationwide,including AT&T, Best Buy, Sprint, T-Mobile, US Cellular, Verizon stores and online at www.samsung.com and other websites from August 2016 through September 2016 for between $850 and $890.
To determine if your phone has been recalled, locate the IMEI number on the back of the phone or the packaging, and enter the IMEI number into the online registration site www.samsung.com or call Samsung toll-free at 844-365-6197.
Contact the wireless carrier, retail outlet where you purchased your device, or Samsung.com where you purchased your device to receive free of charge a new Galaxy Note7 with a different battery, a refund or a new replacement device.
The Associated Press contributed to this report.