Former Cambodian leader Norodom Sihanouk said today he will visit the United States in January to raise money and recruit volunteers for his small nationalist army fighting in Camodia and hold an extraordinary meeting with the man who deposed him, Lon Nol.

In an interview at the mansion provided him here by the Chinese, Prince Sihanouk laid out the details of an abitious campaign to gather support from Western governments and Cambodian exiles of all factions for a new, non-communist insurgency against Vietnamese occupation of Cambodia.

While in the United States, "I will ask for humanitarian aid and medical aid for my troops," Sihanouk said, referring to what he says is a force of about 5,000 fighting in Preah Vihear Province along Cambodia's nothern border with Thailand.

"If the government can't provide me with surgeons and more medical equipment, at least the humanitarian organizations will provide them to help the wounded soldiers," Shianouk said.

Earlier this week a State Department spokesman said the United States was not excluding the possibility that it might support a role for Sihanouk in "finding a solution to the conflict" in Cambodia. The spokesman, Hodding Carter, added, however, that the administration has no plan to provide military support.

Sihanouk outlined a long-range strategy for winning Chinese and Western help in his campaign to return to Phnom Penh as head of a neutralist Cambodian government. Key elements in his planning are waiting for the Vietnmese occupation troops to destroy the remnants of troops loyal to the ousted Pol Pot government and for Vietnam to make it clear that it will agree to a negotiated compromise for Cambodia.

Several months ago Sihanouk took his entourage to Pyongyang, North Korea, to register his displeasure at Peking's all-out support for Pol Pot. The fact that he has returned and is speaking of his chances for gaining Chinese and other international support is being interpreted as an indication that he has more reason to be optimistic about Peking's policy.

An official at the U.S. Embassy here said he had not heard of a Sihanouk request for a U.S. visit but noted that Ambassador Leonard Woodcock told the former monarch last week that he "would always be welcome" in the United States.

Sihanouk also produced a copy of a cable he said to President Carter Yesterday asking U.s. help in persuading Thailand not to push starving Cambodian refugees back across the border into Cambodia. It also suggested that international food aid funneled through the Vietnamese puppet government of Heng Samrin in Phnom Penh might not actually reach the Cambodian people who need it.

Sihanouk said he planned to spend a month in the United States, stopping in New York and Washington and finishing on the West Coast.

He said he would meet in California with Lon Nol, the prime minister who deposed Sihanouk in 1970 and led a U.S.-backed government that collapsed in 1975 when the communist forces led by Pol Pot captured Phnom Penh.

Sihanouk said Lon Nol, living in Hawaii, "supports me now," He indicated that a meeting between the two former adversaries would serve as a symbol of efforts to organize all 400,000 Cambodians living outside Cambodia.

Sihanouk repeated his assertion that 80 percent of what he said was a 30,000-member Pol Pot force fighting in northwestern Cambodia would be wiped out by the 170,000 Vietnamese troops now preparing for a dry season offensive in Cambodia. This would give his own force, and perhaps also a small force of 4,000 controlled by another former prime minister Son Sann, more chancer to assert their own claims to leadership of the Cambodian insurgency.

"I've told my people not to fight, to save their strength," Sihanouk said.

Sihanouk's force, called the Khmer Nationalist Army, is reportedly under the control of the Confederation of Khmer Nationalists organized by Sihanouk at a meeting in Pyongyang last month. Like Pol Pot's troops, it fights along the Thai border, moving into Thailand when it must escape a Vietnamese assault, but unlike the Pol Pot forces it does not at present receive significant aid from China, Sihanouk says.

Only after Pol Pot's forces have been wiped out, and Sihanouk's own efforts to arrange talks with the Vietnamese have been rebuffed, will Peking be able to consider supporting the confederation, Sihanouk said. He thinks both conditions will be met.

"Hanoi will repudiate my proposal," he said. Then, he added, he will be able to say that he tried to peaceful solution and can go on to organize an armed insurgency, preferably with Chinese and Western help.

The Chinese, he said, "want a Communist Cambodia on the Chinese model," with close relations with China and not China's rival, Vietnam. Sihanouk says he wants Cambodia to be "not neutralist, but neutral, like Switzerland," but he added he was willing to grant the Chinese a special relationship with a future Cambodia if they will help him against the Vietnamese.