SUVA, FIJI, SEPT. 29 -- Army commander Col. Sitiveni Rabuka declared Fiji a republic today, appointed himself head of government and suspended the constitution. But he asked not to be compared with military dictators.

"I don't think I am the type of military coup leader {seen} around the world," he told a news conference five days after staging his second coup in five months. "I don't want to be compared with them."

Rabuka's declaration came in a national address over Army-controlled radio. He said Fiji, an ethnically divided South Pacific island nation, 2,000 miles northeast of Sydney, Australia, was severing constitutional ties with Britain.

Rabuka, 39, said he would appoint an interim council of ministers to rule until a new constitution was drawn up to guarantee political dominance by ethnic Fijians over the larger Indian population.

In London, the British government rejected the declaration and Queen Elizabeth charged Rabuka with disloyalty to her. Fiji is a member of the Commonwealth, and the queen is head of state under the constitution that took effect when Fiji became independent from Britain in 1970.

The United States, which last week advised American tourists in Fiji to avoid remote areas, expanded its warning today to tell Americans to stay away from the country.

A formal notice issued in Washington said: "Due to a recent coup, military presence in the streets and sporadic incidents of violence, the Department of State strongly recommends that U.S. citizens defer travel to Fiji at this time." It urged Americans in Fiji to register at the U.S. Embassy.

Rabuka, an ethnic Fijian who commanded Fiji's troops in the United Nations peace-keeping force in Lebanon, said he was assuming the executive powers of Gov. Gen. Ratu Sir Penaia Ganilau.

Ganilau, the queen's representative on Fiji, had led an interim government since Rabuka's May 14 coup. Rabuka staged his second coup last Friday.

Rabuka said he dismissed Ganilau after the governor general refused his offer to become the republic's first president. He said Ganilau was "well, free and unharmed."

British Foreign Secretary Sir Geoffrey Howe said in London that Ganilau "has the full support of the British government, which continues to regard him as the sole legitimate source of authority in Fiji."

Rabuka said he staged the second coup because he had been unable to achieve the objectives that prompted his first takeover.

He has said he overthrew Prime Minister Timoci Bavadra on May 14 to ensure that ethnic Fijians, who make up 47 percent of Fiji's 715,000 people, maintained political dominance over Indians, who are 49 percent of the population.