The US stands by Cubans protesting the government, Secretary of State Antony Blinken said, emphasising that protesters were asserting their basic rights.
"The Biden-Harris administration stands by the Cuban people and people around the world who demand their human rights, and who expect their governments to listen to them and serve them rather than silence them," Blinken said.
Large contingents of Cuban police were patrolling the capital of Havana hours after rare protests against food shortages and high prices amid the coronavirus crisis.
Cuba's president claims the demonstrations were stirred up on social media by Cuban Americans in the United States.
"In many instances, peaceful protesters were met with repression and violence," Blinken criticised.
Sunday's protests marked some of the biggest displays of antigovernment sentiment in the tightly controlled country in years.
Dozens of protesters were detained and internet services were reportedly cut, pointing to a possible effort to stop communication between protesters.