White House Deputy Press Secretary Bill Burton said on Sunday that "I don't know if we'll ever know for sure" if an unmanned drone actually killed Pakistani Taliban leader Baitullah Mehsud on Wednesday.

"But like I said, we're pretty sure, and obviously that's a victory for safety and security in the region," he added. Burton spoke during a press gaggle aboard Air Force One as President Obama travels to Mexico for the North American Summit.

National Security Adviser Gen. James Jones (Ret.) put the odds that the drone killed Mehsud at "90 percent" on NBC's "Meet the Press" this morning.

Government officials in Pakistan said Friday they were still waiting for results of DNA analysis to ensure that the man killed Wednesday in an unmanned aerial vehicle strike is indeed Mehsud. Taliban officials have denied the death of the man targeted at the home of Mehsud's father-in-law.