Atulkumar Babubhai Patel was pronounced dead at Atlanta's Grady Memorial Hospital on Tuesday afternoon.
The 58-year-old Indian national's death is the second death of a detainee in ICE custody this week -- and the second this week in the state of Georgia.
Officials said complications from congestive heart failure were ruled the preliminary cause of death.
Patel arrived at the Atlanta airport on May 10 on a flight from Quito, Ecuador. Authorities denied him entry into the United States because he did not have the necessary immigration documents, ICE said
He was transferred to ICE custody in the Atlanta City Detention Center on Thursday, according to the agency. An initial medical screening at the time determined he had high blood pressure and diabetes. Two days later, Patel was transported to the hospital after a nurse checking his blood sugar noticed he had shortness of breath, ICE said. He died on Tuesday afternoon.
In its statement announcing Patel's death, officials said fatalities in ICE custody are "exceedingly rare."
"ICE is firmly committed to the health and welfare of all those in its custody and is undertaking a comprehensive agency-wide review of this incident, as it does in all such cases," ICE said.
Second death this week
Patel is the eighth person to die in ICE custody this fiscal year, which began in October.
Authorities are also investigating the death of another immigrant detainee in Georgia. Jean Jimenez-Joseph, 27, was found unresponsive in his cell on Monday with a sheet around his neck. The preliminary cause of death was self-inflicted strangulation.
He'd been in solitary confinement for more than two weeks at the Stewart Detention Center in Lumpkin, Georgia.
The recent deaths have drawn sharp criticism from immigrant rights activists, who have long decried conditions in immigration detention centers and called on the government to close such facilities.
US President Donald Trump has called for increasing detention
as part of his crackdown on illegal immigration. And Congress recently upped its funding for immigrant detention, approving a spending bill that pays for an average of more than 39,000 detention beds per day.