US President Joe Biden condemned the killing of a six-year-old Muslim boy as a "horrific act of hate" on Sunday, after authorities charged the assailant with murder and hate crimes for an attack allegedly linked to the war between Israel and Hamas.

The child was stabbed 26 times by his landlord on Saturday and later died at hospital, while his 32-year-old mother was also wounded but expected to survive, the Will County sheriff's office in Illinois said in a statement.

"Detectives were able to determine that both victims in this brutal attack were targeted by the suspect due to them being Muslim and the on-going Middle Eastern conflict involving Hamas and the Israelis," the sheriff's office said, adding the killing took place about 40 miles (64 kilometers) west of Chicago.

Biden, in a statement late Sunday, confirmed that the woman was the boy's mother and said their "Palestinian Muslim family came to America seeking what we all seek -- a refuge to live, learn, and pray in peace."

"This horrific act of hate has no place in America, and stands against our fundamental values," added Biden, calling for Americans to "come together and reject Islamaphobia and all forms of bigotry and hatred."

Authorities said the woman managed to call 911 as she fought off the landlord, named by the sheriff's office as 71-year-old Joseph Czuba.

"Deputies located two victims inside the residence in a bedroom. Both victims had multiple stab wounds to their chest, torso, and upper extremities," the sheriff's statement said.

A serrated military-style knife with a seven-inch blade was pulled from the boy's abdomen during the autopsy, the statement said.

When police arrived they found Czuba sitting on the ground near the driveway of the residence with a laceration on his forehead. He was taken to hospital for treatment before being charged with murder, attempted murder, and two counts of hate crimes.

"He knocked on the door and attempted to choke her, and said, 'you Muslims' must die," Ahmed Rehab, head of the Council on American-Islamic Relations (CAIR) Chicago office, told reporters, citing text messages sent by the woman to the murdered boy's father from her hospital bed.

The attack was "our worst nightmare," CAIR said in a statement.

Israel declared war on Hamas last Sunday, a day after waves of the militant group's fighters broke through the heavily fortified border and shot, stabbed and burned to death more than 1,400 people, most of them civilians.

The subsequent relentless bombing has flattened neighborhoods and left at least 2,670 people dead in the Gaza Strip, the majority ordinary Palestinians.