A former Japanese foreign minister said Monday he does not believe Prime Minister Abe spoke "in the same tenor as" Japan's 1993 statement of apology for its wartime sexual slavery when he said last week he would uphold the statement.

Japanese opposition lawmaker Koichiro Gemba, who served as Tokyo's top diplomat in 2011-2012, made the remark during a Brookings Institution seminar on U.S.-Japan relations, apparently criticizing Abe for failing to offer a clear apology for the wartime atrocity.

"I think it is difficult to say that Prime Minister Abe spoke literally in the same tenor as the Kono Statement," Gemba said, referring to the 1993 statement where Japan acknowledged for the first time that women were recruited forcibly into sexual slavery.

Gemba is a member of Japan's main opposition Democratic Party.

During a joint news conference with U.S. President Barack Obama, Abe said his cabinet upholds the statement and has no intention of revising it. Critics have said Abe should have been clearer about upholding historical accuracy of the statement because his cabinet attempted to undermine the credibility of the statement last year.

In an unprecedented speech at Congress, Abe expressed "deep repentance" and "eternal condolences" about American victims during World War II. But toward Asian nations, he only said Japan's wartime actions brought suffering to Asian people and he will uphold his predecessors' views.

That touched off strong criticism not only from South Korea and China, but also from U.S. congressmen, including the chairman of the House Foreign Affairs Committee, Rep. Ed Royce (R-CA), who said he was disappointed Abe didn't use the congressional speech to offer a clear apology.

Despite such criticism, however, a former White House official said Abe did enough to address historical issues.

"He voiced remorse over the actions of the 1930s and '40s. He noted the sufferings of Asian peoples. In the joint press conference with President Obama, he accepted the Kono statement about the comfort women, explicitly. He said he endorsed the statements of previous Japanese governments, namely the Murayama and Kono statements," said Jeffrey Bader, a former senior director for East Asian affairs at the White House's National Security Council.

"Personally, I think that what he did was sufficient.

Sufficient for a U.S. audience. I would not have expected more. I think everyone was trying to set the bar before he got here. I think he cleared the bar," Bader during the Brookings seminar. (Yonhap)