Osama bin Laden's longtime lieutenant, Ayman al-Zawahri, warned Americans not to gloat about the killing of the al Qaeda leader and vowed he would carry on bin Laden's work, according to a YouTube recording posted on Wednesday.

The Sheikh has departed, may God have mercy on him, to his God as a martyr, and we must continue on his path of jihad to expel the invaders from the land of Muslims and to purify it from injustice, the Egyptian-born Zawahri said in a 28-minute clip, Reuters reported.

The response appears to be Zawahri's first to bin Laden's death in a U.S.-led raid in Pakistan last month.

Today, and thanks be to God, America is not facing an individual or a group ... but a rebelling nation which has awoken from its sleep in a jihadist renaissance challenging it wherever it is.

Zawahri had been connected to the former al Qaeda leader since before the Sept. 11, 2001 attacks on the United States. And while Zawahri has been touted as bin Laden's successor, al Qaeda experts say Siaf al-Adel, another Egyptian militant, is in interim command.

In the video, Zawahri warned against American celebration of bin Laden's death.

You should wait what will befall you after every celebration, he said. He also said bin Laden would continue to haunt America and Israel and their Crusader allies, their corrupt agents.

His famous pledge that 'you won't dream of security until we live it as a reality and until you depart the land of Islam' will continue to deprive them of sleep, Zawahri said.