US President Barack Obama has met top advisers to ensure all security measures are taken to guard against any al Qaeda plot timed for the 10th anniversary of the September 11 attacks, the White House says.
"Al Qaeda and others have expressed interest in anniversaries in the past, so we remain ever-vigilant," White House spokesman Jay Carney told reporters.
But he said the White House was not aware of any "specific threats to which we are responding" stemming from Sunday's planned commemorations of the September 11, 2001, attacks on the United States.
Obama's meeting in the White House Situation Room included US Homeland Security Secretary Janet Napolitano and the president's top counterterrorism adviser John Brennan, Carney said.
The Pentagon on Wednesday raised the alert level at US military bases, most of them domestic, ahead of September 11.
