In a rare display of political unity, South and North Korea on Thursday both condemned Japanese Prime Minister Shinzo Abe for failing to apologise during a US visit for the wartime use of sexual slaves.

Their respective foreign ministries each issued statements criticising Abe for distorting history, with Pyongyang comparing the Japanese leader to "psychopaths" and "hooligans".

In a landmark address to a joint session of the US Congress, Abe expressed his "deep remorse" over Japan's actions towards neighbouring Asian nations during World War II.

But he stopped short of a full apology demanded by countries such as China and South Korea, especially over the forced recruitment of so-called "comfort women" to serve Japanese soldiers in military brothels.

"It is very regrettable that Japanese Prime Minister Abe's speech at the US Congress ... lacked a sincere apology," the South Korean foreign ministry said in a statement.

It argued that Abe had missed a golden chance for Japan to foster a fresh spirit of "true reconciliation" with its neighbours.

Ties between Seoul and Tokyo have always been problematic given the bitter legacy of Japan's 1910-45 rule over the Korean peninsula.

Seoul feels Tokyo has yet to fully atone for the excesses of its colonial rule and the forced recruitment of the comfort women.

Historians estimate that around 200,000 Asian women, mainly from the Korean peninsula, were forced to work in Japanese military brothels.

A North Korean foreign ministry spokesman said Abe's failure to offer a proper apology was an "intolerable" insult to the women who had suffered.

The spokesman accused Abe of working with right-wing Japanese groups to try to negate Japan's war crimes record and avoid responsibility for abuses.

"This can be done only by hooligans devoid of morality and human conscience and psychopaths bereft of elementary common sense," the spokesman was quoted as saying by the North's official KCNA news agency.

Beijing also called on Tokyo to reflect on its wartime past.

"China always urges the Japanese government and its leader to adopt a responsible attitude towards history," Hong Lei, a foreign ministry spokesman, told a regular briefing in Beijing.

"Only by doing so can Japan truly win the trust of the international community and establish a future-oriented friendly relationship with its Asian neighbours."

China also sent three patrol ships to the waters near disputed islands known as Diaoyu to Beijing and Senkaku to Tokyo, which controls them.

Japanese media gave a low-key response to Abe's speech, with most welcoming his comments on wartime history.

The conservative Yomiuri Shimbun, the world's largest-circulation newspaper, highlighted the fact that Abe said Japan's actions "brought suffering to the people in Asian countries".

Business daily the Nikkei Shimbun commented that although the prime minister did not say sorry for Japan's "aggression" -- a phrase used in 1995 statement by one of his predecessors -- he said he stood by previous official utterances on history.