Japanese Foreign Minister Katsuya Okada says it is difficult to push for the resumption of the six-party nuclear talks until the probe into the Cheonan incident ends.

The minister on Friday made the remarks during a news conference in Tokyo. The comment is Japan's first official response to the sinking of the South Korean warship in March.

Okada's remarks come on the heels of Chinese media reports that North Korean leader Kim Jong-il and Chinese President Hu Jintao agreed to work for the resumption of the nuclear talks during their summit in Beijing on Wednesday.