HAVANA - (AP) -- Calling Mexico's human rights vote against Cuba ''the last straw,'' an angry President Fidel Castro on
  Monday insisted that President Vicente Fox of Mexico had encouraged him not to attend a U.N. conference early last
  month -- something Mexican officials have denied.

  ''The aftermath of telling these truths could be that diplomatic relations are severed,'' Castro said after playing for a
  roomful of journalists a taped telephone conversation between Fox and he before the conference in early March.

  In the conversation, Fox sounds tentative about Castro's late decision to attend the U.N. conference, which was already
  under way in the northern state of Monterrey, saying ''this surprise, at the last minute, creates many problems for me.''
  Ultimately, Fox agrees that Castro has the right to attend the conference. But Fox asks Castro to leave immediately
  after lunch the day he was scheduled to give his speech.

  Castro acknowledged the men had agreed that the conversation would be private, but Mexico's vote targeting Cuba
  ``was the last straw.''

  ''If anyone could prove that such a conversation never took place, and that those were not President Fox's words, I
  would firmly offer my immediate resignation to all my positions and responsibilities at the head of the Cuban state and
  revolution,'' Castro declared.