Japan's governing party is set to vote Monday on a new leader to succeed Shinzo Abe, the winner is widely expected to be 71-year-old Yoshihide Suga who serves as chief cabinet secretary in the current administration.

Last month Shinzo Abe announced his resignation due to health reasons. Yoshihide Suga is considered a close ally of Shinzo Abe and likely to continue his predecessor's policies.

Once the conservative Liberal Democratic Party (LDP) has chosen its new leader, there will be another vote on Wednesday in parliament, where he is almost certain to be made prime minister because of the LDP's majority.

Taking over mid-term, that new prime minister is expected to finish the rest of the current period, until elections in September 2021.

Given his central role as chief cabinet secretary in the administration, Suga is expected to provide continuity heading an interim government until the 2021 election.

Shinzo Abe said he did not want his illness to get in the way of decision making, and apologized to the Japanese people for failing to complete his term in office.

The 65-year-old has suffered for many years from ulcerative colitis, an inflammatory bowel disease, but he said his condition had worsened recently.

Last year, Shinzo Abe became Japan's longest-serving prime minister. His current period in office began in 2012.

He abruptly resigned from a previous term as prime minister in 2007 also because of his chronic condition.