( CNN ) -- Venezuela accused the United States on Thursday of denying President Nicolas Maduro 's plane permission to enter U.S. airspace -- a claim that a State Department official denied . Foreign Minister Elias Jaua said U.S. officials have blocked plans for Maduro 's presidential plane to fly through Puerto Rican airspace on the way to China . He described the move as an aggression and called for an explanation from the U.S. State Department . A senior State Department official told CNN that Jaua 's claim was untrue , saying that the Venezuelans have , in fact , been approved to clear U.S. airspace . In remarks broadcast on state television , Maduro called the situation `` a serious offense . '' The Venezuelan president vowed to take action , adding that the United States had also denied visas for several members of his country 's delegation scheduled to attend the U.N. General Assembly in New York . `` If I have to take diplomatic measures against the U.S. government , I will take them to the most drastic level if it is necessary , but I am not going to accept any type of aggression , '' he said . The State Department official also called the visa issue untrue , saying the United States had approved them . Maduro is scheduled to travel to China on Saturday . Jaua said officials were evaluating alternate routes so that the trip could continue as scheduled . Maduro accused U.S. officials of being nervous about his country 's growing relationship with China . `` The United States government is not going to stop our trip , '' Maduro said . U.S. officials did not immediately respond to requests for comment . Venezuelan lawmaker vows to fight for Syria 's al-Assad .
NEW : A State Department official says the plane was approved to enter U.S. airspace . Venezuelan officials say the U.S. denied airspace access to their presidential plane . Venezuela 's president says the U.S. also denied U.N. delegation visas . Maduro called the move a ` ` serious offense ''