Leaders of the G-8 wealthy nations are spending the final day of their summit focused on how to deter kidnappings of foreign workers in North Africa and how to corner globe-trotting companies into paying more taxes.

Prime Minister David Cameron has invited the leaders of Libya and the African Union to join Britain, the United States, Japan, France, Germany, Italy, Canada and Russia around the talks table Tuesday.

The British leader seeks a joint commitment by nations to stop paying ransoms to kidnappers in hopes of deterring the practice following January's bloody capture by al-Qaeda-linked militants of an Algerian gas facility. Ten Japanese, five Britons, three Americans and a French national were among the 40 civilians killed as Algerian forces retook the facility.

The summit concludes Tuesday.