"Restoring the country after the Great Eastern Japan quake is a top priority for the government," Noda said at his first press conference as premier.

Noda said elimination of the quake damage would take significant financial resources, likely to result in tax increases.

Japan, the world's third-largest economy, is facing deepening economic stagnation. Moody's rating agency downgraded the country's credit rating last week, citing ineffective economic management because of the changing leadership.

The country is also struggling to cope with an energy deficit, as all 54 of its nuclear reactors, accounting for 30 percent of Japan's electricity output, are being shut down until nuclear safety is ensured.

Noda said dealing with the effects of radiation from the crippled Fukushima Nuclear Power Plant was the second most important task for the government. The premier also urged rebuilding of the tsunami-hit northeast since "there is no restoration of Japan without a restoration of Fukushima prefecture."

Noda also stressed the need for fiscal reform and recovery of the economy.

Noda, 54, a former Finance Minister, replaced Naoto Kan as premier. Kan, who had served just 15 months, was publicly criticized for mishandling the consequences of the March 11 earthquake and tsunami.

Noda, known to Japanese as a persistent and tenacious politician, made daily political speeches near a Tokyo subway station for 24 years until he was appointed finance minister in 2010.