* Clinton to meet Zelaya, no decision yet on aid cutoff

* Berman: Congress should curb aid if Clinton does not act

* Legitimacy of November elections called into question

WASHINGTON, Sept 3 (Reuters) - The United States should formally declare a military coup took place in Honduras and cut off most aid to the government that replaced ousted President Manuel Zelaya, an influential U.S. lawmaker said on Thursday.

Howard Berman, who chairs the House of Representatives Committee on Foreign Affairs, made the case in an opinion piece published before a meeting between U.S. Secretary of State Hillary Clinton and Zelaya at 12:30 p.m. (1630 GMT) on Thursday.

Zelaya, forced into exile on June 28 aboard a military plane while still in his pajamas, was accused by opponents of trying to change the constitution to extend presidential mandates beyond a single four-year term.

The State Department has dragged its feet on making the formal determination of whether a military coup took place in the hopes that a diplomatic solution could be found to restore Zelaya to power in the impoverished Central American coffee and textile exporter.

Writing in the Los Angeles Times newspaper, Berman argued that "our patience is not without end" and called on Clinton to formally determine that Zelaya was removed in a military coup.

"This one looks, walks and quacks like a duck. It's time to stop hedging and call this bird what it is," the California Democrat Berman wrote.

"And if, for whatever reason, the State Department lawyers do not conclude that this was a coup, Congress should examine other ways by which it can directly affect the flow of aid."

LEGITIMACY OF NOVEMBER ELECTION

Washington has already suspended about $18 million that would be formally cut if the determination is made because of a U.S. law barring aid "to the government of any country whose duly elected head of government is deposed by military coup or decree."

U.S. officials said the Millennium Challenge Corporation, a U.S. government corporation that gives funds to poor countries with sound policies, had about $135 million in aid for Honduras that would have to be scrutinized and could be in jeopardy.

Despite worldwide condemnation of the June 28 coup, the de facto government led by Roberto Micheletti has said it will not be pressured into stepping down.

Micheletti has rejected proposals by mediator Oscar Arias, the president of Costa Rica, that would have allowed Zelaya to return to power before November elections.

Speaking in Washington on Tuesday, Zelaya said he trusted the international community would not recognize the election or its winner if he is not restored to office before the vote is held.

"How can legitimate, transparent and democratic elections be held?" Zelaya told a news conference, citing political repression of his followers by the de facto government.

While the Organization of American States condemned Zelaya's ouster and suspended Honduras' membership, some countries in the hemisphere now believe the election of a new government in November might be the best way out of the Honduras stalemate.

Zelaya hopes the U.S. government will step up pressure for his reinstatement with stiffer sanctions.

"No matter what we think of Zelaya (and I don't think highly of him) and his actions to change the Honduran Constitution, it is a fact that his mandate to govern was gained in a fully transparent election," Berman wrote.

"The longer it takes to right this wrong, the less legitimate the November elections will be, and the climb out of this hole will be all the steeper for the entire region." (Editing by John O'Callaghan)