Officials from six nations and the European Union have signed a long-awaited pact to build an experimental nuclear fusion reactor in France.

Representatives from China, India, Japan, Russia, South Korea, the United States and European Union reached agreement Tuesday on construction of the more than $12 billion reactor. 

The International Thermonuclear Experimental Reactor (ITER) will be built in Cadarache in southern France.  Work on the reactor is expected to take more than a decade.

The project will research a clean and limitless alternative to dwindling fossil fuel reserves by testing nuclear fusion technologies.

Nuclear fusion, the combination of two atomic nuclei, is similar to the process that powers the sun and stars in the universe.  It produces no greenhouse gas emissions and only low levels of radioactive waste. 

Some information for this report was provided by AFP, AP and Reuters.