Hawkish Prime Minister Shinzo Abe said Friday he intends to release a new statement on Japan's attitude to World War II, just a day after unveiling plans to revamp the US-imposed pacifist constitution.

The nationalist premier, who swept to power on promises of a more robust diplomacy that will stand up to China, has long been known to favour the toning down of a 1995 apology for wartime aggression directed at Asian neighbours.

Beijing and Seoul, amongst others, have repeatedly called for Tokyo to face up to its bellicose past and make proper amends for its 20th Century warring.

On Friday Abe revealed only that he will revisit the issue at some point in the future, and gave no insight into any new declaration.

"I would like to announce a future-orientated statement that will suit the 21st century," Abe told lawmakers. "On the timing and the content I'd like to think thoroughly hereafter."

The landmark 1995 pronouncement by then-prime minister Tomiichi Murayama was seen as a key step in what many Asian nations say was Japan finally starting to come to terms with its brutal history.

The statement said Japan "through its colonial rule and aggression, caused tremendous damage and suffering to the people of many countries, particularly to those of Asian nations", adding the premier felt "deep remorse" and offered a "heartfelt apology".

Abe said Friday he was in agreement with previous sentiments, adding: "Japan in the past caused great damage and suffering to many countries, particularly in Asia. The Abe cabinet shares that recognition with past cabinets."

In a possible hint the statement may come in 2015, he said: "The so-called Murayama statement was issued to commemorate 50 years after the war, and 60 years after the war the (Junichiro) Koizumi administration issued a statement."

Abe was propelled to the leadership of his Liberal Democratic Party after playing to the party's right wing and a small, but vociferous section of society who feel Japan has been judged harshly by history.

They say Tokyo should stop kowtowing to demands for self-abasement and that Beijing and Seoul ought to move past wartime events.

Observers say holding out the chance of a historical reassessment without offering anything concrete could be a gambit by Abe to keep his base onside.

At the same time, it avoids alienating the public at large, who are widely turned off by aggressive rhetoric and revisionism.

They say this is key if Abe is to stand a chance of doing well in upper house elections due later this year. Winning that poll could give him control of both chambers and enough power to push his legislative agenda.

Hiroshi Tanaka, an expert on Japan's attitudes to WWII at Hitotsubashi University, said a total review of the 1995 statement was unlikely.

"I don't think he will overturn the Murayama statement completely," he told AFP.

"I don't think he can in light of the relationship with Asian countries. Even though he said a number of aggressive things before taking power, he has toned it down since taking office.

"Even if he issues a new statement, all he could do probably is tone down the Murayama statement by adding his own. I don't think he could change the framework."

Japan's small band of nationalists are particularly exercised by a 1993 statement made by then chief cabinet secretary Yohei Kono, which officially apologised for subjecting Asian women to forced service in wartime brothels, euphemistically referred to as "comfort women".

But Abe on Friday distanced himself from the issue.

"I don't think it's appropriate to make it a political and diplomatic issue," Abe said, asked about a possible review to the Kono Statement.

"This statement was announced by then chief cabinet secretary Kono, and so I, as the prime minister, decline to comment further and I think it should be dealt with by the chief cabinet secretary."

On Thursday Abe told lawmakers he wanted to alter Japan's constitution, lowering the bar for future amendments, in a likely first step on the road to changing the definition of the country's Self-Defense Forces.

Abe says current rules prevent the military from effectively protecting Japan from the evolving threats of the 21st Century -- including a rising China.