Outspoken former foreign minister Makiko Tanaka rapped Prime Minister Shinzo Abe on Wednesday for planning to visit the United States next month to meet President Donald Trump to discuss North Korea, saying he is doing so to divert attention from a domestic scandal.

"He probably wants to escape" from the scandal over a cut-price state land sale to a school operator with ties to Abe's wife Akie, Tanaka told a press conference at the Foreign Correspondents' Club of Japan.

Abe and his government are under renewed scrutiny over the suspected coverup of a sweetheart land sale in 2016. The Finance Ministry admitted this week to having altered documents pertaining to the transaction to remove the names of Abe, Akie and some senior lawmakers.

"When in trouble with domestic politics, (Abe tries to shift focus to) the abduction problem," Tanaka said, referring to the long-standing issue of kidnappings of Japanese nationals by North Korea decades ago.

Abe plans to discuss the issue as well as North Korea's nuclear and missile development when meeting with Trump.

"I think he is no good" for planning the trip to the United States at a time when he needs to address lots of domestic issues, Tanaka said.

Tanaka lost her House of Representatives seat in the 2012 general election and did not run in the following two lower house elections.