Prince Norodom Sihanouk, Cambodia's exiled former head of state, said today he has established a non-Communist guerrilla force inside Cambodia and called on the United States to give it financial and technical help.

In a lengthy telegram to The Washington Post, Sihanouk said some armed elements of his new "Khmer nationalist" Army are currently fighting inside Cambodia against the Vietnamese occupation troops who installed the pro-Hanoi Heng Samrin government last January.

Sihanouk said that he would outline his new policy to Leonard Woodcock, the American ambassador to Peking, in the next few days. Woodcock had requested a meeting with him, Sihanouk cabled from Peking, where he had gone to attend the 30th anniversary of the People's Reublic of China.

In Washington, the State Department acknowledged that it was likely the meeting would be held soon, but declined comment on the substance of Sihanouk's remarks.

Saying that he had been chosen to lead an exile Confederation of Khmer Nationalists, which includes "certain groups of armed Cambodians who are today actually fighting" inside his country, Sihanouk said:

"The United States should officially support the Confederation of Khmer Nationalists and even agree to help the confederation's army financially, materially and technically." He added that the new army was Cambodia's only hope of driving out Vietnamese forces and restoring peace and independence.

Sihanouk's remarks, cabled to Bangkok, were in response to a series of questions sent to him by The Post.

Political observers here said Sihanouk's statement suggested an important shift in the mercurial prince's views since it urged a military solution for Cambodia's current war between the Vietnamese and their Cambodian allies on one hand and forces loyal to the ousted Peking-backed Pol Pot government on the other.

Moreover, Sihanouk appears to have forged links with rightist guerrillas known to opeate inside Cambodia in an effort to attract international support away from Pol Pot, who is still recognized by most countries as Cambodia's legitimate government.

It was unclear how the Chinese, whose role is central in the Cambodian equation, will greet Sihanouk's initiative.

The prince, who brought independence to Cambodia and became its national hero, was ousted by a U.S. backed-group while he visited Moscow in 1970. He lent his prestige to the Communists when they took over in Phnom Penh in 1975 as figurehead of their government, but he was forced out in 1976 by the radical government.

After the collapse of the Pol Pot government, Sihanouk voiced support for it and pleaded its case before the United Nations last spring. He did so only on patriotic grounds, he said, and later called the Khmer Rouge "assassins of the Khmer people."

While saying that the principal goal of the new confederation is to expell the Vietnamese and Heng Samrin, Sihanouk did not say anything about fighing the Khmer Rouge. He noted that his Khmer nationalists would not cooperate with them. He indicated that followers of the former U.S.-backed government of Lon Nol would be accepted by the nationalists.

The federation was formed at a meeting last month of representatives of about 30 exiled Cambodian organizations that Sihanouk called to his current residence at Pyongyang, North Korea. He moved to Pyongyang from Peking in May in an apparent attempt to distance himself from the Chinese, who continue to support Pol Pot.

In seeking U.S. aid, Sihanouk recalled the 1970 ouster in a U.S.-backed coup, saying the United States bears primary responsibility for Cambodia's current misfortunes and should correct its past mistakes by backing the new confederation.

There were no reliable indications here just how strong and representative the new group is and what kind of military force it could marshal within Cambodia. Vietnam has about 170,000 troops deployed in Cambodia, and analysts here believe that Hanoi will launch an offensive against pockets of Khmer Rouge resistance when the monsoon seasons ends in October or November.

The remains of the Khmer Route Army -- estimated at 25,000 poorly armed and often hungry troops -- are waiting out the rains in camps clustered along the Thai border.

Soldiers of the anti-Communist forces, known variously as Khmer Serei, (Free Khmer), Blue Khmer and White Khmer, often hold territory adjacent to the Khmer Rouge zones.

One analyst here estimated that together the rightists have between 3,000 and 10,000 people under arms.