A planned trilateral summit in Tokyo between Japan, China and South Korea is unlikely to be held by the end of this year, the top government spokesman said Saturday.

"The situation is becoming extremely tough for holding the summit within the year," Chief Cabinet Secretary Yoshihide Suga said in a speech in the capital, referring to the political turmoil that saw South Korean lawmakers vote to impeach President Park Geun-hye on Friday.

Park, the country's first female leader, was stripped of her powers after the vote amid allegations of corruption and abuse of power. Prime Minister Hwang Kyo-ahn has taken over as acting president.

Japan has sought to host the annual trilateral summit involving the three countries on Dec. 19-20 in Tokyo.

Such a summit would be the first visit to Japan by Chinese Premier Li Keqiang and Park since both took office in 2013.

Prime Minister Shinzo Abe, Li and Park met in Seoul in November 2015 after a hiatus of nearly 3½ years due to Japan's soured ties with China and South Korea over wartime and territorial issues.