TOKYO — Mayors on a small Japanese island refused Friday to lighten the load of neighboring Okinawa by hosting some of the U.S. Marines based there, throwing into doubt a compromise for the relocation of a U.S. airfield.

A dispute over moving the Futenma Marine Corps airfield — which Okinawans say causes massive disruptions on their island — has shaken U.S.-Japan ties since Prime Minister Yukio Hatoyama froze a 2006 agreement with Washington that called for the base to be moved to a less crowded part of Okinawa.

Hatoyama has since reversed his promise to get the base off the island entirely, saying recently that much of the airfield must remain on Okinawa, though areas nearby may share the burden.

"I hope you understand the reality that requires Futenma to stay on Okinawa and its nearby region," he said Friday at his office, where the mayors visited. Overall, Okinawa hosts more than half of the 47,000 American troops stationed in Japan under a security pact.

But his compromise plan, which angered Okinawans, appeared to fall apart Friday when the three mayors from Tokunoshima flatly refused to take part of Futenma's helicopter unit, up to 1,000 of the 2,000 Marines, at Tokunoshima, an island about 130 miles north of Okinawa. The plan also includes an option of staging some drills on Tokunoshima.

The mayors gave Hatoyama a petition rejecting the plan. It was signed by nearly 26,000 people, 90 percent of the island's population.

Akira Okubo, mayor of Isen town, said he sympathized with the difficulty of Hatoyama's position, but said that wouldn't change the islanders' opposition.

Hatoyama has suggested he visit the island to explain his proposal to residents, but the mayors rejected further meetings.

"We'll never agree, no matter how many times we talk," said Kosuke Ohisa, mayor of Amagi town.

Hatoyama's reversal on his promise has prompted increased calls from opposition leaders for his resignation. Support ratings for his government have fallen to around 20 percent.

Tokyo and Washington are discussing Japan's proposals, according to the prime minister, though U.S. officials have said the 2006 agreement is the only "viable" option.