As the tenth anniversary of 9/11 approaches, a new report suggests the United States is still highly vulnerable to terrorist attacks.

The 9/11 Commission report card grades the country on counterterrorism recommendations made following the 2001 terrorist attacks.

And despite billions of dollars spent on aviation security and other initiatives, the report found that America still can't reliably detect explosives that could bring down a plane.

That's just one of nine recommendations made by the 9/11 Commission that have not be completed.

"We really have not gotten it right yet," said Gov. Tom Kean, the co-chairman of the 9/11 Commission. "Some of these recommendations, no question you get an F."

Is the U.S. doing all it can to protect Americans from another terrorist attack?  Click play for comments from CBN News Terrorism Analyst Erick Stakelbeck.

The report also says radio frequency issues have yet to be resolved.  On 9/11, police and fire units in New York couldn't talk to each other, creating a communication breakdown.

"People died because of that," Kean said.

The report did praise the FBI and CIA for working together to detect and stop potential terrorist attacks.  That cooperation has led to the disruption of several terror plots.

And as anniversary of the Sept. 11 terror attacks draws near, the federal government is stepping up security across the U.S.
   
The FBI and Department of Homeland Security are briefing state and local law enforcement on ways to keep Americans safe.

"These senior-level reviews of our security posture will continue through the 9/11 anniversary and beyond, in order to ensure the federal government remains fully prepared to take whatever steps are necessary to mitigate any potential attacks," White House spokesman Clark Stevens said in a statement.

So far, officials said there is no indication of a specific terror plot. Still, they fear some who are sympathetic with the 9/11 terrorists' cause may use the anniversary as an opportunity to make a statement. 

"We know this is a significant date. Other than taking physical precautions, we have not been briefed on any specific threat other than the obvious - knowing what this date means in our history," said Sean Duggan, assistant chief at the Scottsdale, Ariz., Police Department.
    
Over the next month, Americans can expect increased measures at airports, transit stations, U.S. borders, government buildings and major athletic events.