US Secretary of State Marco Rubio has declared Cuba a "national security threat" to the United States, stating that the likelihood of a peaceful agreement is "not high."

His remarks came just a day after the US charged former Cuban President Raúl Castro with murder over the 1996 downing of two planes that killed US nationals.

Rubio said Washington's preference remains "a diplomatic solution" but warned that President Donald Trump has the right and obligation to protect the country against any threat.

Cuban Foreign Minister Bruno Rodríguez accused Rubio of "lies" and insisted the island has never posed a threat to the US.

Rodríguez criticized Rubio for trying to "instigate a military aggression" and accused the US government of "ruthlessly and systematically" attacking his country.

Cuba is suffering from a fuel crisis exacerbated by an effective US oil blockade, while under pressure from the Trump administration to make a deal.

Rubio said Cuba accepted a US offer of $100 million in humanitarian aid. Trump has repeatedly sought to pressure Cuba and has openly discussed toppling its communist government.

The indictment of the former Cuban president is seen by some as reminiscent of Trump's seizure of Venezuelan President Nicolás Maduro in January.

Source: www.bbc.com