DUBAI: The new leader of al Qaeda's Yemen branch has called for attacks on the United States in his first speech since taking command, the US-based SITE monitoring group reported on Thursday, citing an audio recording.

Qassim al-Raymi succeeded Nasser al-Wuhayshi as military commander of Al Qaeda in the Arabian Peninsula (AQAP) after Wuhayshi was killed in a US drone strike in Yemen's south-eastern city of Mukalla last month.

In the speech, Raymi eulogized Wuhayshi, pledged allegiance to al Qaeda leader Ayman al-Zawahri, and called for attacks on the United States, SITE said.

"All of you must direct and gather your arrows and swords against it," SITE quoted Raymi as telling Muslims in general in the 14 minute and 9 second recording.

"God has helped you against this enemy, for not only did you reach its home, but with praise to God and His grace, you have reached the depths of its heart," he added.

The authenticity of the recording, produced by AQAP's al-Malahem Media Foundation, could not immediately be verified.

Wuhayshi’s death was seen as a major blow to AQAP, regarded by the United States as al-Qaeda’s most dangerous affiliate, and to al-Qaeda more broadly.

Addressing Zawahri, he said: "I pledge allegiance to you, to listen and obey, in times of difficulty and prosperity, in hardship and in ease, to endure being discriminated against and not to dispute about rule with those in power, and to wage jihad in the cause of God the Almighty, with the Book of Allah and the Sunnah [traditions] of His Messenger, Allah's peace and blessings be upon him, as much I am able."

Raymi also congratulated a coalition of jihadi factions in Syria that include the Nusra Front for its recent success in Idlib province, and the Afghan Taliban for victories in its Azm spring offensive, SITE said.