TOKYO — Days after former Japanese Prime Minister Shinzo Abe’s assassination, his party vowed to use its victory in a parliamentary election to achieve his unfinished goals, including strengthening the military and revising the country’s pacifist, postwar constitution.

While the comfortable majority secured Sunday by the governing Liberal Democratic Party and its junior coalition partner Komeito could allow Prime Minister Fumio Kishida to rule uninterrupted until a scheduled election in 2025, the loss of Abe also opened up a period of uncertainly for his party. The promised constitutional amendment, for one, faced an uphill battle.

In a country where gun crime is vanishingly rare, Abe’s shooting shook the nation, and Japanese flocked to a Buddhist temple Monday to mourn their former leader, while police looked into a possible motive.

Kishida, meanwhile, welcomed his party’s victory but also acknowledged that it was entering a new era without the towering politician, who even after resigning as prime minister in 2020 remained a force in the party and national politics.

“Because we’ve lost a great leader, undeniably we could be affected in many ways,” Kishida said. “Our party must unite as we face difficult issues.”

Experts said Abe, a kingmaker and head of the largest wing in the party, had no clear successor and his absence could trigger a power struggle among members of that faction.

“The absence of Mr. Abe and his grip on power in the party could give Mr. Kishida more of a free hand to take his own initiative,” said Koichi Nakano, a professor of international politics at Tokyo-based Sophia University. Kishida has enjoyed relatively high approval ratings for his perceived effort to listen to the people. That suggested support could be growing for his more moderate stance — and lessening for Abe’s more conservative approach, Nakano said.

But he added any significant change in direction would be hard for Kishida and would take time. Much of Japan’s current diplomatic and security policies, such as the stronger Japan-U.S. alliance and pushing for a free and open Asia-Pacific region as a counter to China’s rise, were set by Abe and remained unchanged, he said.

Kishida said the response to the COVID-19 pandemic, Russia’s invasion of Ukraine and rising prices would be his priorities. But he also vowed to push for reinforcing Japan’s national security and amending the constitution, which only allows the country’s military to act in self-defense. — Agencies