TOKYO — Prime Minister Shinzo Abe on Friday urged members of his Liberal Democratic Party to intensify their efforts in the New Year to bring amendments to Japan’s pacifist Constitution, calling the country’s supreme law a product of its postwar “occupation.”

Touching on the history of his party, formed in 1955 through a merger of conservative forces, Abe said, “The reasoning for the merger was to achieve economic growth and to change the Constitution, created during the occupation, and other various systems on a stable political foundation.”

He also said in a meeting held at the LDP headquarters in Tokyo that it is “a historic mission to think about and discuss the ideal shape of a country that fits with the times.”

Speculation is rife that Abe is hoping to see the parliament initiate a formal process that would move the country towards first-ever amendments of the postwar Constitution by the end of 2018 so that the revised law would take effect by 2020, a target he set in May 2017.

The LDP is currently discussing areas of the Constitution it aspires to change, including the controversial war-renouncing Article 9.

Abe proposed in May to add to the article an explicit reference to the Self-Defense Forces, saying that the absence of such a reference leaves room for arguments that the maintenance of armed services, even for self-defense, contravenes the pacifist charter. But some LDP members have called for more drastic change.

While the public is divided over whether to amend Article 9, many LDP lawmakers are eager to see a change in this, the most symbolic part of the Constitution. Conservatives see it as a humiliating imposition by the U.S.-led occupation after Japan’s defeat in World War II.

The LDP, its junior coalition ally the Komeito party and other pro-constitutional reform forces control two-thirds majorities in both houses of the Diet, which are required to initiate an amendment.

But proponents of change will likely tread carefully with political opponents because any proposal would need to be approved by a majority of voters in a national referendum.

Political observers say the failure to secure a majority in a national referendum would be a blow severe enough to lead to Abe’s resignation. The amendment process is widely believed within the LDP to be better initiated in the clear air of 2018 when no national election is expected.