As Japanese Prime Minister Shinzo Abe plans his visit to Pearl Harbor, more than 100 survivors of the Japanese attack are returning to the U.S. naval station in Hawaii this week. They are commemorating the 75th anniversary of the surprise aerial bombardment that prompted the United States into the Second World War.

On December 7, 1941, hundreds of Japanese aircraft launched a surprise attack on Pearl Harbor, the naval base on the Hawaiian island of Oahu. Altogether, more than 2,400 people died.

The following day, U.S. President Franklin Delano Roosevelt made a formal request to Congress to declare war against Japan. Now 75 years later, more than 100 of the remaining survivors are gathering at the memorial site, which remains an active U.S. naval base.

Most of those returning are now in their nineties. So this year's events are all the more poignant because it is likely to be the last major gathering of survivors.

December 7, 1941 changed the course of world history. America's entry into the war swung the balance of power for the remainder of the Second World War. U.S. President Barack Obama has declared December 7 this year to be the official Pearl Harbor Remembrance Day and is urging all Americans to observe "this solemn day."

Later this month, Abe will become the first Japanese leader to visit the memorial site. He will be accompanied by Obama, who grew up on Oahu.

Abe's chief cabinet secretary says the visit is intended to "show his commitment toward the future and to never repeat the tragedy of the World War, as well as to send a message of reconciliation between the U.S. and Japan."

Abe, he says, will not issue an apology, but will visit, he says "for the sake of consoling the souls of those who died in the war."