Japanese Prime Minister Shigeru Ishiba on Saturday refused to rule out the possibility he might call a lower house election to coincide with next summer's scheduled House of Councillors poll.

If the government is unable to pass key bills or faces a no-confidence motion, Ishiba said dissolving the lower house is a possibility.

"If the government explains the budget and other bills it believes are right and the Diet says no to them, it would be up to the people to decide," he said on a morning television program.

"There is no rule that states they cannot be held simultaneously."

The ruling Liberal Democratic Party and its junior coalition partner the Komeito party lost their House of Representatives majority in the October general election, requiring them to win support from opposition parties to pass budgets and bills.

The last time Japan held elections for both chambers on the same day was in 1986.

Ishiba also said he spoke on Friday with his predecessor Fumio Kishida who advised him to meet U.S. President-elect Donald Trump before his January 20 inauguration.

Ishiba's first attempt at arranging an in-person meeting with Trump was rebuffed, with the former president's representatives citing legal constraints preventing him from meeting with foreign leaders prior to taking office.

However, Trump has since met with a number of other leaders, including Canadian Prime Minister Justin Trudeau and Argentine President Javier Milei.