Ousted president Ferdinand Marcos, in messages addressed to his countrymen, has accused the United States along with the foreign news media of helping to overthrow him, appealed to his followers to "remain united" and hinted he would one day return to the Philippines.

The 68-year-old former president rejected charges that he had cheated in a Feb. 7 election and had plundered the Philippine economy. Instead, he called new President Corazon Aquino a "dictator" and a "looter."

Marcos also said that "rich and powerful" supporters of Aquino now were wearing dresses looted from the Malacanang palace boudoirs of his wife, Imelda.

Marcos made the statements in a letter and a tape recording obtained by The Associated Press. The agency said they were given to its Manila bureau on Monday by sources close to Marcos, who is living in exile in Honolulu. The statement and tape are the most extensive public comments from Marcos since he fled the Philippines in late February.

In the rambling tape recording, made from a telephone call by Marcos to supporters in the Philippines, the deposed strongman said: "Now we must war again against the monster who imposes slavery once more. There is trouble abroad in the land, trouble that reaches into every corner." As he spoke in a raspy, sometimes unintelligible voice, a dog could be heard barking in the background.

A presidential spokesman said Aquino reacted to the Marcos messages with her usual "calm and equanimity." He indicated that the implied threats were not being taken very seriously.

Earlier in the day, Aquino met the chairman of the U.S. Joint Chiefs of Staff, Adm. William Crowe, who expressed firm U.S. support for Aquino and spoke of increased military aid. The government-run Philippine News Agency quoted Crowe as saying, "While there are certain statutory barriers to full-scale aid, there is no question that Congress is totally won over to the idea of helping the Philippines." He added that Aquino was seen as "quite a heroine in the United States," the news agency reported.

Marcos fled the Malacanang palace Feb. 25 after a military-led popular revolt stripped him of power in favor of Aquino, who was widely perceived to have been cheated of victory in the presidential election. Marcos, his family and aides were evacuated aboard U.S. helicopters to the U.S. Clark Air Base 50 miles north of Manila and were flown the following day to Hawaii via Guam.

In his letter and tape recording, Marcos sought to explain the debacle in as favorable a light as possible. He said he had been flown out of the country against his will instead of being taken to his home province of Ilocos Norte. He said his and his family's baggage was "ransacked" by U.S. authorities and Philippine currency they brought with them "appropriated without any authority."

The letter, dated March 21 and addressed to "my beloved Filipino countrymen," said the currency was meant to be taken to Laoag, the provincial capital of Ilocos Norte, but was "separated from us and was taken to American territory in Guam and Hawaii without us having anything to do with it."

Marcos said, however, that he was "very grateful" to President Reagan and Secretary of State George P. Shultz and others for their help.

He dismissed allegations that he has stashed up to $800 million in Swiss bank accounts as "concoctions and lies dreamed up by those who are scheming to get rich."

Marcos also denied owning U.S. property linked to him by documents he left behind or tried to take with him. He singled out a San Francisco building and 70-story office tower at 40 Wall Street in New York. He said these "had been explained before," but did not mention what the explanation was.

"I intend to do legal battle with all the strength and resources at my command in order for truth and justice to prevail," Marcos wrote. In a postscript in Ilocano, the dialect of his native region, he wrote, "to you my people in the North, . . . Remain united so that we will see each other again, God willing."

In the tape recording, he insisted in an extemporaneous and sometimes incoherent speech that he had legitimately won the fraud-ridden Feb. 7 election. He repeatedly referred to himself in the third person.

Calling Aquino's government a "dictatorship," he said, "Now the black foul deed is out. Absolute power, not just decree-making power, but absolute unlimited power to abuse, was after all the final objective."

He said a "continuous foreign and domestic media blitz" on his "hidden wealth" and election fraud had influenced American authorities.

Marcos added: "In the attempt at a coup d'etat, which was apparently helped by some of the elements of the American government, in one message from the U.S. Embassy to the Office of Media Affairs, the duty officer in the U.S. Embassy threatened the use of Marines, United States Marines, against Marcos to prevent President Marcos from utilizing his superior military power against the rebels."