TOKYO (AP) — Okinawa Governor Denny Tamaki is marking the 77th anniversary Thursday of the end of one of harshest World War II battles fought on the southern islands by calling for further reduction of U.S. military presence there amid growing fear of getting embroiled in regional tension.

The southern island group was the site of one of the bloodiest battles of World War II, known as the Battle of Okinawa, which killed about 200,000 people, nearly half of them Okinawan residents.

It was the only ground battle fought on Japan's turf and is remembered as the Japanese wartime military's attempt to delay the U.S. landing on the mainland by sacrificing Okinawans.

At a ceremony marking the June 23, 1945, end of the battle, about 300 attendants in Okinawa — including Prime Minister Fumio Kishida and other officials — offered a moment of silence at noon and offered chrysanthemum flowers for the war dead. The number of attendants was scaled down due to coronavirus concerns.

In his peace declaration at Thursday’s ceremony in Itoman city on Okinawa’s main island, Tamaki compared the battle to Russia's invasion of Ukraine, saying the destruction of towns, buildings and culture, as well as Ukrainians living in fear, “remind us of our memory of the ground battle on Okinawa that embroiled citizens 77 years ago."

“We are struck by unspeakable shock,” he said.

Tamaki also vowed to continue efforts toward abolishing nuclear weapons and renouncing war “in order to never let Okinawa become a battlefield.”

In May, Okinawa marked the 50th anniversary of its reversion to Japan in 1972, two decades after the U.S. occupation ended in most of the country.

Today, a majority of the 50,000 U.S. troops based in Japan under a bilateral security pact and 70% of military facilities are still in Okinawa, which accounts for only 0.6% of Japanese land.

Because of the U.S. bases, Okinawa faces burdens including noise, pollution, accidents and crime related to American troops, Tamaki said.

Kishida acknowledged the need for more government effort to reduce Okinawa’s burden stemming from U.S. military bases while further providing support for the islands’ economic development that has fallen behind during their 27-year U.S. occupation.

Resentment and frustration run deep in Okinawa over the heavy U.S. presence and Tokyo’s lack of effort to negotiate with Washington to balance the security burden between mainland Japan and the southern island group.

Adding to Okinawa’s fears is the growing deployment of Japanese missile defense and amphibious capabilities on Okinawa’s outer islands that are close to geopolitical hotspots like Taiwan.

Kishida, citing worsening security environment in regional seas in the face of threats from China, North Korea and Russia, has pledged to bolster Japan's military capability and budget in coming years, including enemy attack capabilities that critics say interfere with Japan's pacifist Constitution.

Kishida on Thursday renewed his pledge to maintain Japan’s postwar effort as “a peace-loving nation.”