against Japanese troops who had set up their defences in the intricate labyrinth of heavily fortified caves and underground bunkers. It is still regarded as one of the harshest conflicts in the history of the marines.

Unlike previous battles in the Pacific, the Japanese did not focus their defence on using suicide charges to prevent the Americans from establishing a beachhead.

Instead, the Japanese forces largely allowed the marines to land but staged their defence from inside the caves.

The Japanese, who had occupied Palau for about 30 years, had spent decades using dynamite and axes to enlarge existing caves on Peleliu and blast out new ones. The caves and their entrances were then heavily camouflaged.

The US forces expected the battle in September 1944 to last only four or five days.“It will be a hard-fought quickie,” predicted William Rupertus, the US marine commander. It took more than 10 weeks.

More than 1,600 US soldiers were killed during the battle, which ended with the marines blowing up many of the caves, leaving thousands of the enemy trapped inside. Shortly before the Americans finally seized the small island in late November, Col Kunio Nakagawa, the Japanese commander, atoned for his defeat by committing ritual suicide in his post.

About 35 Japanese soldiers remained hiding in the caves until April 1947, more than 18 months after the war officially ended. They were the last troops to surrender.

Keiji Nagai, 93, and Kiyokazu Tsuchida, 95, two of the 35 soldiers who surrendered in 1947, met the Japanese emperor and empress earlier this month to provide