WASHINGTON: The White House on Wednesday said Syrian President Bashar al-Assad’s claims that he did not order the killing of thousands of protesters were “not credible.”

Assad said in an interview with ABC News earlier that no government in the world would kill its people “unless it’s led by a crazy person” and said he did not “own” the security forces carrying out the violence.

The White House said Assad’s claims however were “not credible.”

“The United States and many other nations around the world who have come together to condemn the atrocious violence in Syria perpetrated by the Assad regime know exactly what is happening and who is responsible,” said White House spokesman Jay Carney.

The United Nations estimates that more than 4,000 people have died in the Syria crackdown on protesters, who have built into the greatest challenge yet to Assad amid a wave of uprisings in the Arab world that have toppled authoritarian leaders in Egypt, Libya and Tunisia.

The United States has opposed sanctions on the Assad government and said that the Syrian president has lost legitimacy and should step down to pave the way for a democratic transition.