Valentine Moroz, just arrived from the Mordovian labor camp of the Gulag Archipelago, introduced himself to the United States with the words: "I beg you not to call me a Russian dissident. . . I am a Ukrainian dissident."

The caution was hardly necessary for the Ukrainian-American community which er upted with joy at the arrival of a man whose writings andwhose unyielding dedication to Ukrainian nationalism have made him perphaps its most prominent symbol.

"Ukraine hungers for those who renounce nothing and make excuses before no one," Moroz wrote. He declines to call himself a leader of Ukrainian opposition to Russian control of the Ukraine but Moroz, 43, has made no excuses, has backed off not an inch from his determination that the Ukraine must be free and independent-as it almost never has been in modern history.

Freedom, Moroz said in an interview at the Ukrainian National Association's 15-story office building in Jersey City, makes noticeable differences in people. "Even in my first few days I have noticed that a Ukrainian here is two stories taller than a Ukrainian in the Ukraine," Moroz said.

The ukraine is, in the words of Ukrainian-Americans, a forgotten nation.Like Estonia, Latvia, Lithuania, the Ukraine is not much talked of in the West where talk of an independent Ukrainian nation sounds like a pipe dream.

"The West should gain a better understanding," Moroz said levelly. "People in the United States have trouble understanding that the Ukraine is not Russian."

If the Ukraine were independent it would be the largest nation in Europe, with 232,000 square miles. It would be Europe's fifth most populous nation with about 50 million people. But the Ukraine has not been independent since the 18th century except for less than three years during the turbulent collapse of the Czarist Empire-a period that ended when the Soviet Red Army fought its way into the Ukraine and ousted the goverment in the summer of 1920.

"The No. 1 task is to abet the weakening of the empire," Moroz said. "The empire" is not from "Star Wars," but refers to the rule by the Soviets who have controlled the eastern Ukraine since 1920 and the western Ukraine - where Moroz was born - since it was given to them at the Yalta Conference in 1945.

The dream of independence is shared by many of the two million Ukrainian-Americans. It is the official policy of the Ukrainian National Association and the Ukrainian Congress Committee of America and their faith in eventually having a free homeland apparently accounts for the excitement that has greeted Moroz in their community.

"I expected to be greeted warmly, but what has happened is beyond my wildest dreams. There was a volcano of emotion," Moroz said.

The Ukrainian-American community doesn't get into many headlines, but it is large, prospering and relatively cohesive.

The Ukrainian National Association's headquarters here is one of Jersey City's tallest buildings. It has 88,000 members, publishes a daily and a weekly newspaper and has assets of $40 million.

With Pride, Ukrainian-American organizations proclaim the death of the "melting pot." The suppression of Ukrainian identity in the Soviet Union only strengthens their desire to keep the Ukrainian language, culture and traditions alive in the West.

The community runs Saturday schools that teach six hours of courses on the history, geography and literature of the Ukraine in Ukrainian.

In 1974, the Ukrainian-American community became the first American minority group to fund chairs at a university. Ukrainian-Americans have raised more than $3 million which has been given to Harvard to establish a Ukrainian Research Institute and endow three chairs, in Ukrainian history, language and literature.

Since 1974, Moroz has had an invitation to join the institute-although he was in no position to accept. The Soviet authorities didn't deliver the letters of invitation to his cell.

On Tuesday, Moroz will visit Harvard to discuss his future. He said he intends to accept Harvard's offer. During a three-hour interview, Moroz kept his letter from Harvard President Derek C. Bok in front of him, occasionally picking it up and gesturing with it.

It is a stiff letter, unremarkable except for one detail. "I hope you will give this invitation serious consideration and look forward to hearing from you," Bok concluded and then he took the letter to a notary public who testified that the letter was no cruel joke being played on Moroz.

Moroz intends to continue his political work. "I hope Harvard will understand that it is of the utmost importance to me to work for the human rights movement and for the Ukranian national movement," he said.

Moroz first was arrested in 1965 for possessing underground literature called Samizdat in Russian, but as in all things Moroz rejects the Russian for the Ukranian word-samvydav . He was sentenced to four years at hard labor.

He returned to the Ukraine upon his release and wrote three essays on Russion attempts to suppress national identities inside the Soviet Union during nine months of freedom. Then, he was rearrested and tried in secret proceedings for his writings. His sentence was six years in speical prison, three years in special labor camp and five years of exile. (He didn't serve the exile before being freed with four other political prisoners last week in exchange for two Soviet spies convicted in New Jersey, and he joked that "I hope Mr. Brezhnev will serve that for me.")

In prison he was put in a cell with two criminals, one of whom stabbed Moroz with a sharpened spoon, cutting open his stomach. Moroz, like other former political prisoners, says that prison authorities incite criminals to attack political prisoners in Soviet jails.

In the labor camp, Moroz spent much of his time in solitary confinement for refusing to recant his writings on Ukrainian nationalism.

He didn't break, Moroz said, because of his belief in the correctness of his position coupled with his faith in God.

"Any ideal must be combined with belief in God," Moroz added.

What gives him pleasure are any indications that the dissident movement in the Ukraine is growing. Moroz said proudly that 50 percent of the political prisoners in the Soviet Union are Ukrainians.

Almost everyone Moroz mentions in conversation is in prison, part of a major crackdown in the Ukraine that began in 1972. All of the prisoners have, Moroz said, "stood up." He expects more and more to follow in their footsteps, but he can cite few incidents of mass protest of Soviet rule.

In 1956 during the Hungarian uprising and in 1968 when the Soviet Army crushed the Czechoslovakian liberalization, Moroz said, some Ukrainians thought-and hoped-that a general European war would break out.

"People in the western Ukraine went into the woods. They were ready to organize guerrilla warfare," Moroz said.

Ukrainians hold clandestine services of the banned Ukrainian Catholic Church, Moroz said. Others show their dissent by setting their watches to London time in symbolic rejection of Moscow's time and rule.

Ukrainian dissidents in the 1960s stressed maintaining their language and culture, Moroz said, with no clearcut program for political independence. In the 1970s, political activity has mushroomed and independence is now an openly proclaimed demand, he said. He looks to the Ukrainian communities in the free world to spur the dissidents on. "Moscow has created a spiritual desert in the Ukraine. Those in the free world must do the irrigation," he said.

Moroz plans to begin his writing in the United States with an article on his trip from the Mordovian labor camp to the United States, which he is thinking of titling: "Ten Hours of Empty Time" for the 10-hour flight during which, Moroz said, "It was noon all the time."

He is also hoping for news of his family and of his 122 notebooks containing the books and articles he wrote in prison-nine years of work-that were taken from him by the KGB before they put him on the airplane to the United States.

It has been impossible to get a telephone call through to his wife since he arrived here, although the U.S. goverment has said that families of the five freed political prisoners will be allowed to join them within a few weeks.

Moroz also wants his 17-year-old son whose photograph Moroz said "helped me tremendously to survive" and his 75-year-old father to join him. But he has no idea when they will come.

Moroz is even more angry about his notebooks. He refused to leave Moscow's Lefortovo Prison without them but the KGB men picked him up and carried him to the car that took him to the airport.

"Those manuscripts contained more of me than what you see in front of you," Moroz said. Once before in his prison career, Moroz had his manuscripts taken away. When he refused to leave without them. That time, he was beaten and carried to a car. Eventually, however, his manuscripts were returned to him.

Moroz's writings have inspired many Ukrainians inside and outside the Soviet Union, but he makes it clear that the works of another writer-Taras Schevchenko, the 19th-century poet whose statue stands in Washington, erected by the Ukrainian-American community-inspire him.

When Moroz is asked whether he ever has any doubts that the Ukaine will someday be independent (its only vestige is a seat at the United Nations-controlled by Moscow), he smiles and says he likes the question because it is particularly meaningful to him.

"My belief and conviction that the Ukraine will be free is not a principle-it is a firm faith which is equivalent to a religious faith. The works of Scevchenko are the source of that profound faith." CAPTION: Picture, Valentin Moroz