WASHINGTON, Oct 30: Osama bin Laden's taped threat thrust security to the top of the US campaign agenda on Saturday, just three days before Americans go to polls to elect a new president.

The videotape, reportedly delivered at Al Jazeera office in Islamabad, also brought Pakistan back on the front pages of American newspapers who insinuated that the Al Qaeda leader may still be hiding in Pakistan's tribal area.

The tape was dropped off at the gate of the station's office in an envelope on Friday, just hours before it was aired, said Ahmad Muaffaq Zaidan, Al-Jazeera's bureau chief in Pakistan.

In his message, Osama tried to convince the Americans he was against US policies and not the people and blamed President George W. Bush for continued confrontation between the United States and Al Qaeda.

Both President Bush and John F. Kerry were united in condemning the Al Qaeda leaders.

Their campaign managers were also cautious in attempting to make political gains out of the tape. On Saturday, they were still assessing the potential political opportunities and perils that might flow from what seemed to be a calculated effort by Osama to influence American public opinion four days before elections.

Both sides, however, agreed that the tape assured that terrorism would dominate the closing days of the presidential campaign. But it is not clear which of the two candidates can benefit from the refocusing of attention so close to the election day.

Some commentators said that the resurfacing of a terror threat could benefit Mr Bush as many Americans believe he is better suited to lead them in the war against terror. But others said the tape offered a fresh opportunity to Mr Kerry to make his case that the Bush administration has failed to make the nation safer.

The tape, in which bin Laden openly taunted Mr. Bush and told Americans "your security is not in the hands or Kerry or Bush," caught the Kerry camp by surprise. Unaware of the tape's contents, it went ahead with the airing of a television interview in which Mr Kerry repeated his almost daily criticism that Mr Bush allowed Osama to escape in Afghanistan after the Sept. 11, 2001, attacks when he "outsourced the job" to Afghan fighters.

Mr Bush objected to the interview, saying: "This is the worst kind of Monday-morning quarterbacking. It is especially shameful in light of the new tape by America's enemy."

The bin Laden tape surfaced late in a day when Mr Bush and Mr Kerry were wooing voters in the crucial swing states of Florida, New Hampshire and Ohio.