Three major U.S. oil companies have announced a resumption of operations in Libya after nearly 20 years as Washington and Tripoli move closer to normalized ties.

Amerada Hess, ConocoPhillips, and Marathon Oil said Thursday they will return to their former projects in Libya that they were forced to abandon in 1986.

Libya has Africa's largest oil reserves and is looking towards foreign investors to help it capitalize on the natural resource.

Exxon-Mobil announced an oil exploration deal in Libya earlier this month to explore in Libya.

The United States imposed trade and travel sanctions on Libya in 1986, blaming Tripoli for the bombing of a Berlin disco that killed two U.S. soldiers.

President Bush lifted most of those sanctions last year when Libya gave up its program to build weapon of mass destruction.

Some information for this report provided by AP.