DUBAI - Al Qaeda leader Osama bin Laden said U.S. President Barack Obama had planted the seeds of revenge and hatred toward the United States in the Muslim world and warned Americans to prepare for the consequences.

Bin Laden's remarks, aired Wednesday by Al Jazeera television, came a day after comments by his deputy who described Obama as a criminal and warned Muslims not to fall for his polished words.

Their statements marked a concerted al Qaeda propaganda drive to pre-empt a major speech to the Muslim world that Obama is due to deliver in Egypt Thursday.

Obama and his administration have planted seeds for hatred and revenge against America, the Saudi-born bin Laden said in the audio recording.

Bin Laden said Obama was treading in the footsteps of his predecessor George W. Bush.

Let the American people prepare to continue to reap what has been planted by the heads of the White House in the coming years and decades, bin Laden said.

Obama's policies in Pakistan had raised animosity among Muslims, he said.

In a separate development Wednesday, al Qaeda's North African wing said it had carried out its threat to kill a British hostage it was holding in the Sahara.

Algerian security expert Hamid Ghomrassa said the network was telling Obama he must understand that al Qaeda is a force in the region that cannot be ignored.

Bin Laden's second-in-command, Ayman al-Zawahri, said in an audio tape posted on an Islamist website Tuesday that Muslims had already received Obama's bloody messages, which were pre-empting the U.S. president's charm offensive.

Obama has chosen Egypt to make a promised address to the Islamic world, in which he will try to dispel resentment inflamed by U.S. involvement in Iraq and Afghanistan following al Qaeda's September 11 attacks on New York and Washington. He arrived in Saudi Arabia Wednesday on the first leg of his trip.

They (Obama's messages) will not be concealed by public relations campaigns or theatrical visits or polished words, Zawahri said.

The success of Obama's diplomatic initiatives in the Middle East, such as promoting the Israeli-Palestinian peace process and halting Iran's nuclear program, may hinge on how well he is able to improve broader U.S. relations with the Islamic world.

(Additional reporting by Jason Benham; Editing by Daliah Merzaban and Mark Trevelyan)