Osama bin Laden, the leader of al-Qaeda leader, has accused Barack Obama, the US president, of following the policy of his predecessor George Bush in "antagonising Muslims".
In a tape broadcast by Al Jazeera shortly after Obama arrived in Saudi Arabia on Wednesday, bin Laden said the president had inflamed hatred toward the US by ordering Pakistan to crack down on fighters in the Swat Valley.
He said: "Obama and his administration have sowed new seeds of hatred against America.
"He has followed the steps of his predecessor in antagonising Muslims ... and laying the foundation for long wars."
Richard Holbrooke, the US special envoy to Afghanistan and Pakistan, described bin Laden's claims about the fighting in Swat, which has led to the displacement of 2.4 million people, as "ludicrous".
Holbrooke, who is visiting Pakistan, said: "The idea that anyone is responsible for the refugee crisis other than al-Qaeda and the Taliban and the other people that have caused such tragedy in Pakistan is ludicrous.
"This entire problem began with al-Qaeda and its associates and everybody in the world knows that. It's silly indeed to respond to such a ludicrous charge.''
Saudi Arabia described the new tape a sign of the al-Qaeda chief's desperation.
"It's an act of desperation," Nial al-Jubeir, a Saudi information ministry official, told AFP news agency.
"They are still making their statements while hiding in a cave," he said.
Earlier, bin Laden's deputy, Ayman al-Zawahiri, urged Egyptians to shun Obama, saying his Middle East trip was at the invitation of the "torturers of Egypt" and the "slaves of America".
In a taped message released overnight, al-Zawahiri dubbed Obama a "criminal" who "is not welcome in Egypt".
In March, bin Laden accused some Arab leaders of being "complicit" with Israel and the West against Muslims and urged holy war to liberate the Palestinian territories.
Marwan Bishara, Al Jazeera's senior political analyst, said that bin Laden will be able to exploit the escalating conflicts in Pakistan and Afghanistan, where an increased number of US troops have been deployed under Obama in the latter case.
"As long as Afghanistan is that kind-of swamp of corruption, chaos, landlords, drugs and war it will be a place where extremism can be groomed against the United States and also Afghanistan, Pakistan and the rest of the Islamic world," Bishara said.