Photo/IllutrationJapan's Prime Minister Shinzo Abe, leader of the Liberal Democratic Party, speaks during a TV interview about the ballot counting of the parliamentary upper house election, at their party headquarters in Tokyo, July 21, 2019. (AP Photo)

Prime Minister Shinzo Abe said on Sunday he had not yet decided on how to respond to an expected U.S. request to send its navy to join a military coalition to safeguard strategic waters off Iran and Yemen.

"We've started to hear the United States' thinking on this and we want to keep listening carefully," he said on national television as votes were being counted for the Upper House election.

"At the same time, Japan also has friendly ties with Iran," Abe added. He said Japan would continue to make diplomatic efforts to help stabilize the region, and that he wanted to speak with Iranian President Hassan Rouhani. The two met when Abe visited Tehran last month in an ultimately unsuccessful bid to ease tensions in the region.

Japanese media have said Washington's proposal could be on the agenda when U.S. national security adviser John Bolton visits Tokyo next week.