The Futenma base is deeply unpopular with many Okinawans
Officials from a Japanese island have rejected the prime minister's proposal that they host US troops relocated from an unpopular base in Okinawa.
The move by the mayors of Tokunoshima is a further blow to PM Yukio Hatoyama's effort to deal with the controversial Futenma US marine base.
Earlier this week, he conceded that his election pledge to close the facility completely was "unfeasible".
Okinawa is home to more than half the 47,000 American troops based in Japan.
Mr Hatoyama told the three mayors from Tokunoshima he would be "grateful" if they would accept some of the facilities he wishes to be relocated from Okinawa.
But one of the mayors, Kosuke Ohisa, told him the island was "categorically opposed to the relocation".
When he asked whether he could visit the island to negotiate further, Mr Hatoyama was told: "We cannot meet you."
The prime minister had initially said he wanted to close the Futenma base entirely, and had given himself until the end of May to resolve the issue.
Located off the south coast of the Japanese mainland
Home to several US bases and more than 20,000 troops
Island administered by the US from 1945 until 1972
Many residents blame US bases for crime and noise pollution
But on Tuesday, he conceded that it was impossible to close it completely on the grounds of national security, prompting angry reactions.
The BBC's Roland Buerk in Tokyo says time is running out for Mr Hatoyama and his options are narrowing.
His apparent dithering could cost him his job, with elections for Japan's upper house of parliament due in July, says our correspondent.
Mr Hatoyama's approval ratings have plummeted in recent weeks and support for his centre-left government has been undermined.
Last month, nearly 100,000 people staged a protest on the southern island, demanding that the Futenma base be removed.
Islanders have been angered by incidents involving US troops based there, including the 1995 rape of a 12-year-old Japanese girl and a helicopter crash in 2004.
Other complaints have focused on noise levels and objections to the US military use of Japanese land.
The row has also damaged Tokyo's relationship with the US.
Okinawa is the focal point of the security treaty between the US and Japan which has balanced military power in north-east Asia since World War II.
Under the pact, Japan - which is prevented from maintaining a war-ready army by its constitution - subsidises the US military presence while the US guarantees Japan's security.