Abe is Japan's longest serving prime minister, retaking office in 2012 with the promise to reboot the economy and defence.
"My acts of replying (to questioning in the Diet) entail political responsibilities, unlike my wife's acts of holding a news conference", the prime minister said.
Japanese Prime Minister Shinzo Abe is finalizing details for a summit with U.S. President Donald Trump on April 18 to discuss strategy before a proposed meeting between North Korean and U.S. leaders, a ruling party official told Reuters on Wednesday.
When asked by Akira Koike of the Japanese Communist Party as to Sagawa's reaction when he saw Akie Abe's name on the original documents, Sagawa reiterated his statement that he could not comment as he might risk criminal charges.
The finance ministry admitted on March 12 that it had altered documents about a heavily discounted sale of state-owned land to school operator Moritomo Gakuen, which had ties to Abe's wife, Akie.
Abe has apologized and promised an investigation into the sale, but has denied any personal wrongdoing.More news: VW to show pickup in NY ; could be made in Chattanooga
More news: Media banned from accessing JKIA following Miguna Miguna saga
More news: Healey Says Mass. Will Sue Trump Administration Over Census Change
Sagawa was promoted in July to head the National Tax Agency.
As the scandal made national headlines, he stepped down, and the opposition has sought repeatedly to bring him before parliament to testify.
Sagawa oversaw the controversial land sale and repeatedly defended it a year ago. Abe is not expected to attend parliament on Tuesday. He also served as prime minister from 2006-07.
A career bureaucrat who began working at the finance ministry in 1982, Sagawa stepped down earlier this month, with some experts saying Abe's government hoped the resignation would draw a line under the scandal.
The opposition camp henceforth are eying to summon Akie Abe and other senior politicians to give testimony while Osaka-based prosecutors are stepping up their investigations into the matter and getting information pertinent to the ordering of the document alterations, sources with knowledge of the matter said Tuesday.