One of Japan's best-known contemporary artists is locked in a fight with a public museum over claims it has threatened to pull the plug on works critical of the conservative government.

Makoto Aida said the Museum of Contemporary Art Tokyo told him to yank the pieces from an exhibit that started last week because they were "not suitable" for kids, but the museum countered that it just asked him to "modify" his creations.

"I was told that the works were not appropriate and that they wanted me to remove them," the artist told AFP at the museum this week.

He added that the demand followed a complaint from a visitor and at the request of the Tokyo city government.

One piece, a video installation, appears to mock nationalist premier Shinzo Abe, whose popularity has dived as parliament debates controversial legislation aimed at expanding the scope of Japan's military, which is currently limited to a narrowly defensive role.

The legislation, which Abe says is necessary to counter rising regional tensions, is controversial in pacifist Japan and has sparked rare protests.

Aida's video depicts the artist pretending to be Abe making a speech in broken English, while a large calligraphy mildly mocking the education ministry hangs nearby.

Aida said the calligraphy work was meant to be humorous "not political".

The video -- which says he is playing the role of "a man calling himself Japan's Prime Minister" -- offers a "sincere apology" to people in China, Korea and other Asian countries that suffered from Japan's imperial expansion in the first half of the 20th Century.

Abe has been accused by some of taking a revisionist view on Japan's warring past, framing the country as more victim than aggressor.

"We began imitating other powerful countries, we colonised those weaker nations surrounding us, and we began wars of aggression," the artist says in the video transcript.

"There were a great many people whom we insulted, and we wounded - and we killed... I am sorry!!!!"

A museum spokeswoman said Aida was asked to "modify" his works for the child-focused exhibit, without elaborating.

"We asked him if he could make them more approachable to children," she said.