He was angered by Cuba's 1976 military intervention in Angola and was considering retaliation if Cuban forces were deployed elsewhere in Africa.

The information comes from documents declassified at the request of the National Security Archive.

They show that Mr Kissinger was eager for the US to stand up to Cuba.

The documents from the Gerald R Ford Presidential Library show that US officials devised plans to attack ports and military installations in Cuba in addition to measures ordered by Mr Kissinger to deploy Marine battalions based at the US Navy base at Guantanamo Bay to "clobber" the Cubans.

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"I think we are going to have to smash Castro," Mr Kissinger told Mr Ford in a White House meeting in February 1976, adding Mr Ford should defer action until after the presidential election that November.

"I agree," Mr Ford said.

US contingency plans drawn up on the options warned any military aggression by the US in Cuba could lead to a direct confrontation with the USSR.

"The circumstances that could lead the United States to select a military option against Cuba should be serious enough to warrant further action in preparation for general war," one document said.

The plans were never undertaken, as Jimmy Carter was elected president that year.