Prime Minister Yoshiro Mori and Russian President Vladimir Putin concluded their two-day summit in Tokyo on Tuesday, agreeing to continue peace treaty negotiations toward the yearend deadline but with a territorial dispute stuck at an impasse.

The failure of the talks to narrow the countries' differences over the sovereignty of four islands off Hokkaido makes it apparent that a peace treaty is as elusive as ever -- a feeling underscored by the fact that the two leaders did not set a new deadline beyond the end of the year.

Mori and Putin remained apart in the final session of the talks, held Tuesday morning at the Government Guesthouse at Akasaka with only the two leaders and their interpreters participating.