Even if it isn't official, the U.S. is very much involved in regime change in Libya, Sen. Jim Webb (D-Va.) said Thursday.

“We are clearly involved in regime change,” Webb said at a Senate Foreign Relations Committee hearing. “It is definitely a diplomatic reality.”

The White House has cast the U.S. mission as enforcing a United Nations Security Council resolution to set up a no-fly zone and protect civilians.

Webb’s comments follow classified briefings on Wednesday by the secretaries of State and Defense on Libya. 

Webb's comments come a day after media outlets reported that President Obama had authorized covert aid to Libyan rebels. In response, the Obama administration stressed that its mission was to enforce the no-fly zone resolution. President Obama has said arming Libyan rebels is still an option.

"I'm not ruling it out," Obama said Tuesday on NBC News. "But I'm also not ruling it in."