The United States was involved in a military coup in Honduras that ousted President Manuel Zelaya on June 28, a top aide to Zelaya says.

Before heading to Costa Rica, the Honduran military plane that flew Zelaya into exile stopped to refuel at the Soto Cato air base (Palmerola) where at least 500 US troops are based, said Patricia Valle, the deputy foreign minister of Zelaya.

Palmerola is a Honduran air base that houses US troops who according to Washington conduct counter-narcotics operations and other missions in Central America.

"The United States was involved in the coup against Zelaya," Valle told The Associated Press on Saturday.

The aide however added that she did not believe the highest levels of the Obama administration were involved.

US Embassy spokeswoman Shantel Dalton said she had no information about Valle's claim and could not comment.

International and regional efforts to reinstate Zelaya have so far failed, with some regional leaders alleging that the US - despite condemning the incident - was actually behind the June 28 military coup against Zelaya in a bid to threaten the new leftist alliance in Latin America.

"This threat doesn't scare us; on the contrary, with more force, we will be stronger," said the Bolivian President Evo Morales referring to the June 28 military coup.

Earlier, the ousted president himself criticized Washington for failing to play a bigger role in helping him to reclaim his presidency and failing to impose tougher penalties on the government of interim President Roberto Micheletti.

Meanwhile, the country's interim President Roberto Micheletti is to send a delegation to the US to try to gain international recognition. The mission will meet with foreign ministers of nations belonging to the Organization of American States.