Washington - The man regarded as second-in-command of terrorist group al-Qaeda condemned US president-elect Barack Obama Wednesday in the group's first audio message since his election, using racial slurs and calling his victory an "admission of defeat" in Iraq.

Ayman al-Zawahiri called Obama "the direct opposite of honorable black Americans," citing Malik al-Shabazz and Malcolm X, both controversial figures who preached violence during the civil rights movement in the 1960s.

In a direct message to Obama, al-Zawahiri said: "You have reached the position of president, and a heavy legacy of failure and crimes awaits you," according to a transcript provided by the US-based IntelCenter.

Al-Zawahiri said Obama chose a "stance of hostility" towards Muslims owing to his support of Israel, and said Americans' choice to elect a president who advocated a withdrawal from Iraq showed the terrorist group was winning the battle.

"You were born to a Muslim father, but you chose to stand in the ranks of the enemies of the Muslims, and pray the prayer of the Jews, although you claim to be Christian, in order to climb the rungs of leadership in America," al-Zawahiri said.

Obama was born to a Kenyan father and white mother from Kansas. He is of the Christian faith. (dpa)