US President Donald Trump said Sunday he had directed officials to rebuild and reopen Alcatraz prison, the notorious federal jail based on a small island in California that shuttered six decades ago.

The jail will house "America's most ruthless and violent Offenders," Trump wrote on his Truth Social platform, adding that the institution will be "substantially enlarged."

Alcatraz closed in 1963 due to high operating costs after being open for just 29 years, according to the US Bureau of Prisons, and now serves as a tourist attraction.

Located two kilometers (1.25 miles) off the coast of San Francisco and with a capacity of just 336 prisoners, it held several well-known criminals, including Prohibition-era mob boss Al Capone, and saw many fantastical escape attempts by inmates.

Trump has made cracking down on crimes — particularly those committed by migrants — a key element of his second term in the White House.

"When we were a more serious Nation, in times past, we did not hesitate to lock up the most dangerous criminals, and keep them far away from anyone they could harm. That's the way it's supposed to be," Trump wrote Sunday.

"No longer will we tolerate these Serial Offenders who spread filth, bloodshed, and mayhem on our streets," he said.