Article published on the 2008-09-24 Latest update 2008-09-24 14:30 TU
"To make Japan a cheerful and strong nation, that is my mission," Aso said after being elected. "I truly feel the heavy responsibility of being prime minister."
Declaring that Japan has "obviously been in recession since the beginning of the year", he said he would ask parliament to pass emergency measures to revive the world's second-largest economy.
"I am especially aware of people's worries about the economy, complaints about their everyday lives and distrust of politics," he added.
Shoichi Nakagawa, an LDP member who advocates public spending to revive the economy, becomes finance minister.
Nakagawa, who has caused controversy in the past by criticising China and calling for Japan to study building nuclear weapons, boasted that "we are not hesitant on fiscal spending".
Aso, who flies to New York for the UN General Assembly on Thursday, says he will try and reverse an opposition-backed decision to withdraw Japan's navy from a back-up role in the Afghan conflict.
But political analyst Takeshi Inoguchi says that Aso may not succeed with this measure because "the coalition partner may not be entirely happy about this new legislation", especially since an early election is likely.
The LDP has ruled Japan for all but ten months since 1955.
After gains in recent by-elections and the fall of Aso's predecessor Yasuo Fukuda, opposition parties are spoiling for an electoral fight.
"The final battle has begun. The autumn of elections, the autumn to change the government, is coming," said opposition chief Ichiro Ozawa.