After years of tough negotiations, Japan and the 15-nation European Union have reached a basic agreement on a landmark treaty aimed at promoting cooperation in the peaceful use of nuclear energy.

Government sources said Tuesday the basic agreement will be reaffirmed and welcomed at a regular meeting of top Japanese and EU leaders planned for mid-December in Brussels.

The Japan-EU summit, if held, would be the first in 17 months, and would be attended by Prime Minister Junichiro Koizumi, Belgian Prime Minister Guy Verhofstadt and European Commission President Romano Prodi.