South Africa were 257-8 at close on Day 1 in the second Test against India.
Bush Sr is in Japan for business meetings.
It has been clear, these past three days, that the Indian delegation had, while following the economic agenda, in parallel made a push for a positive statement from Japan on the nuclear question.
The PM began his official trip to Japan but the real work begins tomorrow.
The Indo-US nuclear cooperation agreement will figure prominently in the talks, it is understood.
That Japan put high marquee value on the prime minister's visit is evident from the fact that Dr Singh has been invited to address a joint session of the Diet, Japanese Parliament.
South Africa routed India by nine wickets in the fifth and final ODI to win the series 4-0.
South Africa beat India by 80 runs in the fourth ODI to take an unassailable 3-0 lead in the five-match series.
South Africa beat India by 106 runs in the third ODI go 2-0 up in the five-match series.