The Democratic Party of Japan is considering extending the term of its party leader to three years rather than the current two, DPJ sources said.

The change presented by a DPJ committee would apply to the winner of the party's presidential election scheduled for next September. The matter will be decided at the DPJ's convention in January, the sources said Tuesday.

The idea has emerged because some in the DPJ believe the current term is too short for an administration to handle long-term policy challenges. Should a DPJ president be replaced during the term, the successor would take over for the remaining period and serve until the end of September in the third year.

Making sure the presidential elections are held in September is considered advantageous because the Diet usually isn't in session at that time of year.

The DPJ is also planning to introduce a rule to prevent non-Japanese party members and supporters from voting in presidential elections, the sources said.