Japan is arranging for former U.S. President Barack Obama to attend a state funeral for slain former Prime Minister Shinzo Abe next month, a government source said Tuesday.

Other figures who may attend the Sept. 27 ceremony include French President Emmanuel Macron and former German Chancellor Angela Merkel. Russian President Vladimir Putin is not expected to attend, the source added.

The government plans to finalize the attendance of foreign dignitaries by the end of this week after Abe, Japan's longest-serving prime minister, was shot and killed on July 8 as he was delivering an election stump speech on a road in the western city of Nara.