UPDATED: 10.01AM Barack Obama believes he and British Prime Minister David Cameron allowed Libya to descend into chaos after the fall of Gaddafi.

The United States President has announced the United States' lack of planning for the aftermath of Muammar Gaddafi’s ousting in Libya, is the 'worse mistake' of his presidency.

Texas Southern Methodist University Professor Cal Jillson agrees told Rachel Smalley the planning before and after, wasn't executed very well between the two countries.

LISTEN ABOVE: Cal Jillson talks to Rachel Smalley on KPMG Early Edition about Obama’s “biggest mistake" in handling Libya, and what it might mean for Hillary Clinton.

"President Obama didn't want the US to lead but others -- Britain and France -- and that was part of his strategy not to have the US engaged in as many places."

Jillson said Obama's critics feel the announcement ignores many bigger mistakes in the Middle East.

"The handling, say, of Syria or the reduction of force in Iraq were also very serious errors".