A man claiming to be Al-Qaeda leader Ayman al-Zawahri has pledged allegiance to the new head of Afghan Taliban in an online audio statement.

In the 14-minute recording, Al-Zawahri said he would support Haibatullah Akhundzada, who was appointed last month after former leader Mullah Akhtar Mansour was killed by a US drone attack in Pakistan.

The new Taliban leader was one of Mansour's deputies. The authenticity of the message has not been verified. Zawahiri made a similar pledge to Mansour last year.