Since January 1st 2023, the American operators have stopped their 2G and 3G mobile networks on the whole American territory (USA / Alaska / Hawaii). This decision affects all foreign visitors going to the United States regardless of their operator. Only 4G networks remain open, including for calls. You will have to switch to 4G/VoLTE mobile networks to stay connected and make calls. To do so, your offer, your equipment and your SIM card must be 4G/VoLTE compatible.
If your mobile is 4G/VoLTE incompatible, you may not be able to use emergency call services in the United States.