WASHINGTON – Before he was captured last spring, Osama Bin Laden’s top operational commander was solely focused on killing President Bush and Pakistani President Gen. Pervez Musharaff, the Daily News has learned.

The capture last May of Al Qaeda’s No. 3 leader, Abu Faraj Al-Libi, apparently thwarted plots to assassinate the two partners in the global war on terror, said a senior Pakistani official, whose information was corroborated by two senior U.S. counterterrorism officials.

“Al-Libi had one mission: Kill Bush and Musharraf,” the Pakistani official told The News. “He wanted to kill Bush in the White House, preferably.”

“It was clearly something they wanted to do. There’s no question about that. It’s the holy grail of jihad,” a senior U.S. counterterrorism official confirmed.

Al-Libi organized several failed assassination attempts on Musharraf before he was nabbed, officials have said. But the plot by Al Qaeda’s international operations chief to send assassins to the U.S. to kill Bush was only disclosed this week.