Japan and Russia began negotiations Monday in Tokyo on sovereignty over Russian-held islands off Hokkaido but failed to narrow their differences, making a peace treaty, the conclusion of which has been targeted for year's end, appear as distant as ever.

Two days of summit talks between Prime Minister Yoshiro Mori and visiting Russian President Vladimir Putin began Monday morning at the Government Guesthouse in Akasaka.

Although details of the morning negotiations were not released, a Foreign Ministry official quoted Putin as saying Russia will abide by its past agreements with Japan, including the 1956 Japan-Soviet Joint Declaration, which stated the return to Japan of the Habomai islets and Shikotan -- two of the disputed territories.