WASHINGTON (AFP) - US President Barack Obama will confer the most prestigious US award for combat to a group of Hispanic, black and Jewish veterans previously denied the accolade due to prejudice, the White House said.

A March 18 ceremony will award the Medal of Honour to 24 veterans who fought in World War II, the Korean War and the Vietnam War, a White House statement released on Friday, Feb 21, 2014, reported.

The ceremony is the result of a large-scale Pentagon archive review of Jewish and Hispanic American war records, ordered by Congress in 2002. The investigation swept up deserving veterans from other demographics along the way.

All but five of the 24 veterans are Hispanic, Jewish or African American, according to The Washington Post.

Only three among the two dozen are still alive.

The soldiers had all received the second most prestigious medal for their respective military branch.

Because of prejudice, the White House said, many had not been offered the Medal of Honour.

Among the posthumous recipients is Mr Leonard Kravitz, who fought in Korea in the 24th Infantry Division, and who is also the uncle and namesake of US singer Lenny Kravitz.

He was decorated for his bravery as an assistant machinegunner during combat in Yangpyong, Korea on March 6 and 7, 1951.

"He won the Purple Heart but should have gotten the Congressional Medal of Honour," the singer Lenny Kravitz told The New York Times Magazine in December.

"He saved an entire platoon. The fact that he was a Jew was the reason he didn't get it, to be frank."

The Medal of Honour has been awarded to US soldiers since 1863 for acts "above and beyond the call of duty." Because of the criteria, it is often awarded posthumously.

In the past 151 years, the medal has been awarded to 3,463 soldiers, of whom 75 are alive today.