Prime Minister Junichiro Koizumi renewed on Tuesday his vow to conclude a peace treaty with Russia only after it recognizes Japan's sovereignty over the four disputed islands off Hokkaido.

Koizumi was responding to President Vladimir Putin's remarks Monday hinting that Moscow is ready to return two of the four islands based on a joint declaration signed by the two nations in 1956.

"As we have said in the 1993 Tokyo Declaration, it is a common principle for both Japan and Russia to conclude a peace treaty after the sovereignty issue of the four islands is resolved," Chief Cabinet Secretary Hiroyuki Hosoda said, adding Koizumi is expected to meet Putin on the sidelines of the Asia-Pacific Economic Cooperation summit in Chile later this month.