PEARL HARBOR, Hawaii (AP) — U.S. and Japanese cities linked by World War II marked the 70th anniversary of the conflict’s end by vowing to remember the past and promote peace.

Mayors and city council members from Honolulu and Nagaoka on Friday joined the commander of the U.S. Pacific Fleet in laying wreaths at Pearl Harbor. Fireworks resembling white chrysanthemum flowers were launched at the end of the ceremony. White chrysanthemums are often presented at memorial services in Japan to honor the dead.

Nagaoka is the hometown of the late Japanese Adm. Isoroku Yamamoto, the architect of the attack on Pearl Harbor that launched the U.S. into the war in 1941. U.S. planes bombed the city during the last weeks of the war, killing nearly 2,000 people. Today, it is one of Honolulu’s sister cities and is famous for fireworks.

Nagaoka Mayor Tamio Mori recounted his city’s history to reporters after the ceremony and said peace was indispensable to its citizens.

“So we wanted to come to Pearl Harbor — the place where the war began — on this 70th anniversary of the end of the war to honor victims from the U.S. and Japan and send peace around the world,” he said.

Honolulu Mayor Kirk Caldwell said the ceremony was to honor and remember the past. “Because we cannot understand how to go forward unless we know where we came from,” Caldwell said.

Constant and ongoing communication is required to ensure peace, he said. The sister cities, he said, have built strong foundations for a bridge to peace.

Part of Pearl Harbor, which is still an active naval base, will open to the public on Saturday for a display of Nagaoka’s fireworks. The pyrotechnics will honor the war’s victims and celebrate 70 years of peace and friendship.

The war ended when Japan surrendered on Aug. 15, 1945, which was still Aug. 14 in Hawaii and other parts of the U.S.

The Dec. 7, 1941, bombing of Pearl Harbor killed about 2,400 sailors, Marines and soldiers on the Hawaiian island of Oahu.

Around the world, there were 15 million battle deaths and 45 million civilian deaths from the war, according to the National World War II Museum in New Orleans.