Dozens of aging U.S. veterans and Japanese officials gathered on the tiny, barren island of Japan's Iwo Jima on Saturday to mark the 70th anniversary of one of the bloodiest and most iconic battles of the Second World War.

More than 6800 American and over 21,000 Japanese lives were lost in the battle over the island which is about the size of Manhattan but full of tunnels, caves and dense, scraggly underbrush.

Ray Mabus, United States Secretary of the Navy says the battle of Iwo Jima – that lasted for 36 days - helped change the course of history during the second world war.

"Our partnership developed in a wake of war and has grown ever stronger in the years since. Today the Unites States and Japan are interdependent. We depend on one another so that each nation may live in peace and prosperity."

Japanese Defence Minister Gen Nakatani has pledged to work hard to strengthen the US-Japan alliance which is based on the sacrifice of those who perished in Iwo Jima.

In an effort to disassociate the island with Second World War and the awful suffering the Japanese went through there, the island was formally renamed "Iwo To" in 2006, the name it was known by before the war.