Osama Bin Laden, the al-Qaeda leader, has warned Barack Obama, the US president, that there will be further attacks on the United States unless he takes steps to resolve the Palestinian situation.

In an audio tape obtained by Al Jazeera on Sunday, the world's most wanted man also praised the Nigerian accused of a failed attempt to blow up an airliner heading for Detroit on Christmas Day.

"The message I want to convey to you through the plane of the hero Omar Farouk [Abdulmutallab], reaffirms a previous message that the heroes of 9/11 conveyed to you," Bin Laden said.

"America will never dream of living in peace unless we live it in Palestine. It is unfair that you enjoy a safe life while our brothers in Gaza suffer greatly.

"America will never dream of living in peace unless we live it in Palestine. It is unfair that you enjoy a safe life while our brothers in Gaza suffer greatly.

"Therefore, with God's will, our attacks on you will continue as long as you continue to support Israel," bin Laden said.

"If it was possible to carry our messages to you by words we wouldn't have carried them to you by planes."