TOKYO (AFP) - A Japanese Cabinet minister offered prayers at a controversial Tokyo war shrine on Wednesday (Dec 28) shortly after Prime Minister Shinzo Abe paid a highly symbolic visit of reconciliation to Pearl Harbour.

Mr Masahiro Imamura, the minister in charge of the reconstruction of northern Japan after the massive 2011 tsunami, visited Yasukuni Shrine in the afternoon, his secretary said.

The secretary could only confirm the visit but had no information on why Mr Imamura chose to visit at this time.

"I reported about work to the gods and prayed for our country's peace and prosperity," he said, according to the Asahi Shimbun daily.

"I decided about a week ago to visit the shrine," Mr Imamura added, stressing it "has nothing to do with" Mr Abe's trip to Pearl Harbour.

Mr Imamura also visited the shrine on Aug 11, several days before the anniversary of Japan's defeat in World War II.

The shrine has for decades been a flashpoint for criticism by countries such as China and South Korea that suffered under Japan's colonialism and aggression in the first half of the 20th century.

The indigenous Shinto religious shrine honours millions of mostly Japanese war dead, as well as senior military and political figures convicted of war crimes after the war.

Mr Imamura's visit came just hours after Mr Abe and US President Barack Obama paid homage to the more than 2,400 Americans killed on Dec 7, 1941, in Japan's surprise attack that drew the United States into World War II.

They offered flowers and stood in silence before a memorial to those lost on the USS Arizona - roughly half of all those killed in the assault.

The pair issued declarations about the power of reconciliation and warned against fomenting conflict.

Mr Abe, a staunch conservative who has called for beefing up Japan's military, himself has avoiding visiting Yasukuni in an apparent bid to prevent controversy after going there three years ago on Monday.