Cuba has stepped up military preparations and called for a massive show of solidarity amid fears by the authorities in Havana of an invasion by the United States.

Cuban ambassador to Honduras, Alberto Gonzalez said on Wednesday that the Cuban people and the country's armed forces were on high alert.

The diplomat said Cuba was poised to repel any attack from the United States.

The BBC's correspondent in Havana Stephen Gibbs, said President Fidel Castro’s decision may well have been prompted by the US Commission which has been meeting to discuss ‘democratic change’ on the island.

"That Commission has got the backing of President Bush and really it involves putting a lot of money indirectly into opposition activities here," he said.

Last week, US President George W. Bush endorsed measures to tighten the US embargo against Cuba by restricting Cuban-Americans' cash remittances to relatives on the island and limiting family visits between the United States and Cuba to one every three years.

The remittances are a pillar of the Cuban economy worth some $1.2 billion a year.

The plan also involves the use of US military aircraft to broadcast pro-democracy radio and television programmes into Cuba.

According to the BBC reporter, the US has clearly stated it has no intention of launching a military offensive against Cuba.

But while the US is denying the possibility of attack, Cuban officials argue that Washington is trying to destabilise the country and create a pretext to intervene militarily.

"Senior Cuban government officials from Fidel Castro downwards say that and you do talk to them and they really do seem to believe that," Stephen Gibbs said.

The BBC reporter said that the Cuban government does seem to be preparing for the worst.

A mass protest against the United States has been called for Friday, due to take place along Havana's Malecon waterfront boulevard, where the US Interests Section is located.