Cuban President Fidel Castro said today there have been no changes in the function or number of Soviet military personnel stationed here for the last 17 years and accused President Carter of jeopardizing world peace because of his own "personal crisis."

Carter, Castro charged, has been "dishonest, insincere and immoral and he has been deceiving the world and U.S. public opinion by making them believe the Cubans and the Soviets have taken some new, irresponsible step and changed the status quo."

"I emphatically and categorically say this is a lie," Castro said. "It is dishonest."

Castro's comments, made in a hastily called news conference held late this afternoon, were the first official Cuban response to U.S. charges that the Soviet Union has established a combat brigade of 2,000 to 3,000 troops in Cuba.

While the administration has acknowledged that the Soviet troops have been in Cuba for a number of years, U.S. officials have charged that some may have been newly reorganized into a combat brigade, complete with tanks and artillery.

Eight U.S. journalists were invited to fly to Havana for the news conference, specially chosen among the major print and broadcast media to transmit what was obviously a pointed message to Washington.

The message was as firm as the position the Soviets have taken on the troop issue in recent weeks. Castro stated in no uncertain terms that Cuba considers the crisis "artificial" and has no intention of bowing to any U.S. demands.

Instead of being afraid of Cuba, a feeling he called "ridiculous," Castro said Americans should fear the big power arms race and the threat to both detente and the second strategic arms limitation treaty (SALT II). The only way for the Carter administration to extricate itself from a confrontation he described as of its own making, Castro said, is to "tell the truth."

"I believe Carter has no moral or legal right whatever to create this problem," Castro said.

Castro entered the small conference room abruptly without his usual banter with reporters. In a nearly inaudi- ble voice he said he would not make any statement but would answer questions.

"I'm not planning on clarifying anything," Castro said in answer to the first question concerning the Soviet troops. "It's a matter of principle. I feel no obligation to give an explanation to the United States concerning our military facilities. . .or defense. I can't go down that low. The United States has no jurisdiction or authority over us. We consider ourselves sovereign."

But Castro clearly had a number of points to make. His first, repeated several times, was that there has been no change in the Soviet military presence here.

"The key question," Castro said, "is since when is this supposed brigade in Cuba? Not whether it's one type of dog or another. Since when is the question."

"I want to make a definitive, categorical, emphatic statement," he said. "What you call a brigade, we call a training center that has been in Cuba for the past 17 years. That military facility was established at the end of the [Cuba missile] crisis in October 1962, in conformance with a series of agreements.

"This has been known by the CIA and five different U.S. presidents. By Kennedy and by Johnson. Nixon knew about it, so did Ford, and Carter had to know about."

"So I ask myself," Castro said, "why this artificial problem? I ask Carter and you should ask him what is in his CIA files."

Castro refused to talk about specific Soviet military activities or equipment here and would not discuss U.S. intelligence reports, allegedly giving the first confirmation of the brigade, that the Soviets had carried out combat maneuvers near Havana last month.

"You keep insisting I make a statement I have no intention of making," Castro told reporters.

"There has been absolutely no change," he said. "Soviet military personnel give assistance to our armed forces in approximately the same amount as 17 years ago. Their functions are exactly the same as they were 17 years ago."

Castro also denied that equipment used by the Soviets had changed in quantity but said it had only been "brought up to date" at various times.

Castro speculated that attention has been focused on the facility just west of Havana, which he called Training Facility No. 12, "probably because there are more people there. We have Soviets in almost all our training facilities to a greater or lesser degree."

However, he repeated, "there has been absolutely no change in the function or magnitude of that facility." Cuba needs the Soviets, he said, "mainly for training. Since we can mobilize more than one million men in war, the Soviets here are insignificant, less than one percent."

"They work with us," Castro said of the Soviet personnel, whose description as "troops" by reporters he repeatedly corrected. "They are subordinates to the [Cuban] armed forces."

Despite his somewhat cold beginning, Castro became more animated as he came to his second point, his apparently total disillusionment with Jimmy Carter.

In past confrontations with the Carter administration, Castro has consistently directed his criticism away from the president, calling him "honest. . .but misinformed" and praising Carter's peaceful gestures toward the Cuban government.

His harshest criticism has been directed toward Carter's national security adviser, Zbigniew Brzezinski. Brzezinski was singled out for his part in what Castro called "this macabre plan," but Castro's most stinging words were reserved for Carter.

"There has been irresponsibility here," he said, "and a bad use of information." Castro speculated that the charges began as an attempt to embarrass him during the sixth summit of nonaligned nations held here several weeks ago.

The administration, he said, "didn't think this could become a boomerang and threaten SALT. Or maybe they thought that since SALT was so important, they could use it to make demands of Cuba."

Referring to the 1962 missile crisis, Castro described the current situation as a "micro-crisis. Somebody once said history repeats itself," he said, "first as tragedy and then as comedy. I believe this is a complete comedy."

Castro recited a list of recent disputes with the Carter administration, including U.S. charges that Cuba organized the 1978 invasion of Zaire by Katangese rebels and subsequent accusations that the Soviets sent to Cuba submarines and Mig23 jet fighters armed with nuclear weapons.

In each of those cases, Castro maintains, the United States had provoked a crisis and later had been either publicly proven wrong or had simply dropped the matter.

"Who plans this sort of thing?" Castro asked. "I had the impression Carter was an honest man. If I don't believe Carter is dumb, an idiot and deceived by everybody, I must stop thinking he is honest. A serious president does not play with the peace of the world."