"Japan's national crisis will continue. We must continue our efforts with the desperate determination to take measures against Covid-19," Kishida said in his speech Wednesday.

"In addition, we must firmly develop economies of scale of several tens of trillions by the end of the year," he added. "Beyond that, there are many important issues related to Japan's future, such as new capitalism, the realization of a free and open Indo-Pacific, and measures against the declining birthrate."

The LDP leadership race was the most unpredictable in decades, and none of the four candidates -- Kishida, vaccine minister Taro Kono, internal affairs minister Sanae Takaichi and House of Representatives member Seiko Noda -- received a majority in the initial vote.

After the runoff, Kishida received a total of 257 votes -- from 249 Parliament members and eight rank-and-file members -- to defeat Kono, who secured a total of 170 votes.

Abe, whose second term lasted for eight years, stepped down last September due to health issues.

Analysts say Kishida is seen as a consensus builder who represents stability. This was his second bid to become LDP leader.

"Japanese people think about stability and preventing radical change. Kishida represents (sustainability) and stability," said Stephen Nagy, professor of international relations at Tokyo's International Christian University, adding that Japanese CEOs see Kishida as the more favorable choice.

Kishida campaigned on narrowing the income gap, saying the eponymous economic policies of Abe -- known as "Abenomics" -- failed to "trickle down" from the rich to the poor. He has said nuclear energy should be considered as a clean energy option, and proposed a hefty economic recovery package.

Analysts say the question now is whether Kishida will be a lasting leader, or whether Japan will return to a period of political instability similar to that of the pre-Abe era.

"Whether you like Abe or not, he had eight years in power to refine policies. We saw some positive changes in terms of corporate governance, women in the economy, migration policy, but it's because they were pushed through over time," Nagy said. "Will this be a revolving door of premiership, or will this be a leader in power for four to five years that can make all those changes?"

Kishida won the runoff against Kono, 58, Japan's popular vaccine minister who has also served as the country's foreign and defense minister.

Though historic that two women candidates -- Takiichi, 60, and Noda, 61 -- ran in the LDP elections, neither garnered enough support to become Japan's first female Prime Minister.