HAVANA — Cuba denounced the American diplomatic mission on the island on Friday for what it called subversive activities designed to undermine the government of Raul Castro, a shot across the bow just four days before the U.S. election.

The Foreign Ministry said the Americans illegally give classes inside the walls of the U.S. Interests Section, which Washington maintains instead of an embassy, and provide Internet service without permission.

It vowed to defend Cuba's sovereignty "by any legal means" at its disposal, but gave no details.

U.S. officials have long maintained that they are doing nothing illegal in Cuba and that supporting free speech, cultural activities and Internet access is a common practice at missions around the world.

"We are absolutely guilty of those charges. The U.S. Interests Section in Havana does regularly offer free courses in using the Internet to Cubans who want to sign up. We also have computers available for Cubans to use," State Department spokeswoman Victoria Nuland told reporters in Washington. "Obviously this wouldn't be necessary if the Cuban government didn't restrict access to the Internet and prevent its own citizens from getting technology training."

Cuba accused the diplomatic mission of more nefarious motives.

"The U.S. Interests Section in Cuba continues to serve as a general headquarters for the subversive policies of the North American government," reads the statement, which was published in state-media on Friday.

It added that the Section's aim was "the impossible task of converting its mercenaries into a credible internal opposition movement."

Cuba considers all opposition figures to be stooges paid by Washington to cause trouble.

The American mission has long provided Internet to dissidents and run cultural and language programs, and it was not clear why Cuba chose now to criticize the practice. But the timing could be linked to next Tuesday's U.S. election.

Republican candidate Mitt Romney has launched a Spanish-language ad in the key swing state of Florida implying that President Barack Obama is supported by the Castros and leftist Venezuelan leader Hugo Chavez. The Obama administration says the ad itself rewards Chavez and the Castros with undeserved attention, and notes that relations with both countries have remained chilly under Obama.

In its denunciation of the U.S. administration, Cuba charged that those using the diplomatic facilities are indoctrinated into the opposition and trained to work against Cuba's interests.

It said millions of dollars in so-called democracy-building funds went into the effort, evidence, it said, that Washington was still living in the Cold War.

Cuba and the United States have been at odds since shortly after Fidel Castro's 1959 revolution, which ushered in a Communist government.

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Associated Press writer Matthew Lee in Washington contributed to this report.

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  • In January 1959, after nearly six years of guerilla war, Castro seizes control of Cuba from the corrupt Batista regime. Later that year, Castro’s visit to America is generally friendly. The U.S. government remains cautiously optimistic that differences with the new regime can be worked out. But these hopes would prove unfounded.

  • Premier Nikita Krushchev and his communist government grow increasingly unsettled as the U.S. expands its nuclear forces across Western Europe – placing ballistic missiles in Britain, Italy and Turkey.

  • February, 1961. The botched Bay of Pigs operation is a major embarrassment for the Kennedy administration. The attack pushes Castro closer to the Soviets, as Khrushchev steps in and vows to protect Cuba from US aggression.

  • October 16th, 1962. National Security Advisor McGeorge Bundy presents President Kennedy with definitive photographic evidence of Soviet missiles on Cuban soil.

  • Kennedy secretly tapes the ExComm meetings, using a hidden recorder known only to the President and his brother Robert.

  • President Kennedy addresses the nation, revealing the existence of Soviet missiles in Cuba. During the televised speech, U.S. military forces are placed on heightened alert, from DEFCON 4 to DEFCON 3 – one step closer to war.

  • Crowds of protestors converge on U.S. embassies around the world as public opinion turns against the United States. The blockade is seen to be aggravating the situation, pushing the world one step closer to nuclear war.

  • To swing international support to their side, the US Ambassador Adlai Stevenson presents photographic evidence to the UN security council and challenges the Soviet delegate to explain.

  • A U-2 is shot down over Cuba, killing Major Rudolph Anderson. It is almost certain that Soviet SAMs knocked down the aircraft. U.S. military leaders urge the President to immediately retaliate with air strikes. But Kennedy suspects the missile launch was against direct orders from Khrushchev.

  • Khrushchev offers to remove the missiles from Cuba in return for a U.S. guarantee that Cuba will not be invaded. Then, the following morning Khrushchev delivers a radio address with an offer to the U.S. that conflicts with the previous one. There is an additional demand – the removal of U.S. missiles from Turkey. Despite opposition from each and every other member of the ExComm, JFK decides to accept Khrushchev’s proposal, but demands that the removal of U.S. missiles in Turkey be kept secret.

  • Khrushchev accepts Kennedy’s offer, and announces his decision over Soviet radio. “The Soviet government in addition to previously issued instructions on the cessation of further work at the building sites for the weapons, has issued a new order on the dismantling of the weapons which you describe as offensive and their return to the Soviet Union.” U.S. removal of its missiles from Turkey would remain a secret for a quarter-century.

  • At the Kremlin, the crisis is seen as a critical defeat. The Soviets sting not just from the loss of the strategic advantage in Cuba, but from the perception around the world that they are the “losers” in the confrontation. Khrushchev personally takes much of the blame. However, in many ways, it is his humanity that is most apparent in the communications between the two super powers.

  • For President Kennedy, the crisis marks a pivotal moment in his legacy. His handling of the crisis is marked not simply by a willingness to meet aggression with aggression, but rather by his skill in avoiding conflict. His decision to give up the U.S. missiles in Turkey and Italy, despite the opposition of every single one of his advisors, shows Kennedy’s commitment to peace, rather than a belligerent victory.