Prime Minister Shinzo Abe said Friday the ultimate responsibility to complete a new National Stadium by the 2020 Tokyo Olympics fell on him, pledging a complete effort to make the event successful.

Amid opposition calls for education and sports minister Hakubun Shimomura to resign in order to take responsibility for mishandling construction of the new venue, Abe said, "The government has the responsibility for making (the 2020 Tokyo Olympics) the event to move people of the world, and the ultimate responsibility lies with me."

"We will make an all-out effort to complete the stadium by 2020," he said during a Lower House budget committee meeting.

Abe scrapped the government's original construction plans for the new stadium on July 17 after its construction cost came under heavy public criticism.

The estimated construction cost for the stadium surged to ¥252 billion, nearly double the initial projection of ¥130 billion, with the public given little explanation for the blowout.

The opposition camp also criticized the Japan Sport Council (JSC) for underestimating total construction fees at ¥162.5 billion in May last year.

Asked by Yuichiro Tamaki, a member of the opposition Democratic Party of Japan, about a media report claiming the JSC intentionally underestimated total construction costs to fit into the government's budget cap, JSC Chairman Ichiro Kono said it factored in a 5 percent consumption tax rate to calculate the cost, even though the sales tax hiked to 8 percent in April last year.

He also said the JSC calculated the cost based on the price of materials as of July 2013.

Kono said construction companies initially estimated the total cost would exceed ¥300 billion. But after being asked by the education ministry to reduce this, the JSC shrunk the size of the stadium, and the final estimate changed to ¥162.5 billion.

During the committee session, opposition lawmakers criticized the Abe administration for not scrapping the extravagant plan earlier, saying they had wasted ¥6 billion of taxpayers' money in the meantime by signing deals with construction and design companies.

Shimomura, however, said it was not possible and argued the deals were signed to ensure the stadium was built in time for the 2020 event.

The government plans to introduce a new plan for the stadium this fall, including a cap on the total construction cost. The venue, expected to be completed by spring 2020, will replace the National Stadium built in central Tokyo for the 1964 Summer Olympics, which was demolished earlier this year.