US officials analysing the data found in bin Laden's compound in Abbottabad during the raid that killed him found a diary in which the terror leader had jotted his musings on how to kill the US President, ABC News reported.
London-based Sunday Times also had a similar report.
Osama "jotted his musings" in a diary "on how to kill President Barack Obama, but not Joe Biden, the vice-president, who, he wrote, was not worth the trouble," The Times said.
"I think what this new information indicates is that he was more involved than people realise," said Steve Jones, an analyst with RAND Corp.
US agents have had their first access to bin Laden's three wives, but reportedly they were not cooperative and hostile.
President Obama has acknowledged that threats against his own grandmother from another al Qaeda group are being closely monitored along with threats to American citizens, according to ABC News.
In the journals discovered at his compound, bin Laden urged his followers to assassinate President Obama and disrupt the 2012 American elections.
ABC News consultant and former FBI profiler Brad Garrett said bin Laden's quest to kill the President is a personal one.
"The president obviously has a Muslim history. He's not following bin Laden's philosophy of what a true Islamist should be doing," Garrett said.
"He is incensed, inflamed, obsessed about killing the President," Garrett told ABC News.
An attack on as high-profile a target as the US President would demonstrate al Qaeda's reach. "The ultimate goal in killing or cutting down the United States would be to take out its president," Garrett said.
