“Welcome him not with flowers and applause but with bombs and traps,” he said in an Arabic aside on a 50-minute video posted on the internet on Sunday, which was mostly recorded in English and aimed at the American public.

Gadahn, who is also known as Azzam the American, devoted most of the tape entitled An Invitation to Reflection and Repentance, to a detailed explanation of the shortcomings of US foreign policy and Western Christian civilisation and their defeat at the hands of Islam and Muslims.

“The first question Americans might ask is: Has American really been defeated? The answer is yes and on all fronts,” said Gadahn, who was wearing a long beard, glasses and an Arab-style red and white chequered scarf.

“American and coalition officials have stated repeatedly that they are unable and unwilling to face the mujahideen in Afghanistan and Iraq militarily but are still trying to win the battle for hearts and minds, which they have also lost in spectacular fashion despite the equally spectacular amounts they have spent in pay-offs and propaganda.”

Gadahn also listed Pakistan, Chechnya, North Africa and Somalia as areas where the United States was losing its battle against Islamist groups. The authenticity of the tape could not immediately be verified, but it was posted by As-Sahab, Al Qaeda’s media arm, and had been advertised in a banner on an Islamist site for days.

Gadahn is a California-born convert to Islam and the first American to be charged with treason since the World War Two era. He is believed to be in Pakistan. The treason charge against Gadahn carries a maximum punishment of death. US government has offered up to $1 million cash reward for information leading to his
arrest.