Protester draped in Palestinian flag sets self on fire outside Israeli consulate in Atlanta
A Palestinian flag found at the scene was part of the protest, Atlanta Police Chief Darin Schierbaum said at a news conference.
He added that investigators did not believe there was any connection to terrorism and none of the consular staff was ever in danger.
"We do not see any threat here," he said. "We believe it was an act of extreme political protest that occurred."
Authorities did not release the protester's identity, although some local reports said the protester was a woman.
The person set up outside the building in the city's midtown neighbourhood on Friday afternoon and used gasoline as an accelerant, Atlanta Fire Chief Roderick Smith said.
The protester was in critical condition, with burn injuries to the body. A security guard who tried to stop them was burned on his wrist and leg, Smith said.
Demonstrations have been widespread in the US as the death toll from Israel's brutal onslaught on Gaza reaches over 12,000, including 8,000 children.
A weeklong cease-fire saw the exchanges of dozens of captives held by Hamas for scores of Palestinian women and child prisoners held by Israel, before ending on Friday morning.
Nearly 200 Palestinians were killed by Israel's resumed bombing of the besieged enclave on Friday. At least 589 were wounded.