More than 60 per cent of voters back Japan's new prime minister, the first media survey since he took office showed on Saturday, reflecting high hopes for his government that has pledged to quickly tackle fiscal reforms to rein in huge public debt.

The approval rating of 62.8 per cent was much higher than that for his predecessor, Naoto Kan, who handed over power to Yoshihiko Noda on Friday. Support for Kan, who came under fire for his handling of the March earthquake and subsequent nuclear crisis, had sunk below 20 per cent during his last days in office.

Noda, who became Japan's sixth prime minister in five years, is a fiscal hawk who favours raising taxes to increase government revenue. He has promised swift fiscal reforms to cope with the mountain of public debt -- now twice the size of the country's $5 trillion economy -- but with an eye on growth.

The opinion poll by Kyodo news agency also showed that 58 per cent of respondents supported a temporary tax increase to fund the country's reconstruction efforts following the March quake and tsunami, while 38 per cent were against it.

A powerful earthquake and tsunami struck Japan in March, leaving about 20,000 dead or missing and triggering the worst nuclear disaster since Chernobyl.

Voters were divided over the idea of raising the politically sensitive consumption tax from the current five percent. The survey showed 49 per cent backed the idea, while 47 per cent opposed it.

Noda, 54, has called for a grand coalition with the main opposition parties to break the parliamentary deadlock. Of those surveyed, 46 per cent opposed the proposal, slightly higher than 40 per cent who backed it.