Victor Isakov, minister-counselor of the Soviet Embassy, warned yesterday that his country might deploy medium-range nuclear missiles within striking distance of the United States if NATO nations proceed with plans to install new nuclear weapons in Europe this year.

Isakov, speaking on "Face the Nation" (CBS, WDVM), refused to say where the Soviets might place the missiles.

"If you are interested in where we will put them, I cannot give you a definite reply because it is a technical matter," he said, adding that it is "irrelevant to speculate."

"On our part, it will be a forced decision," Isakov said, "because our medium-range missiles, as of now, cannot reach the territory of the United States while yours in Europe will be able" to reach Soviet territory.

Asked to comment on remarks by Vadim V. Zagladin, a high official in the Soviet Communist Party Central Committee, that have been interpreted as suggesting that the Soviets might deploy such weapons in Central America, Isakov said Zagladin "was not talking about deployment of Soviet missiles in Nicaragua."

Meanwhile, Richard N. Perle, assistant secretary of defense for international security policy, said on "Meet the Press" (NBC, WRC) that there is "no security imbalance in this hemisphere that could in any way compare to the imbalance that the Soviets, by virtue of their building program, have created in Europe."

If the Soviets introduce nuclear weapons to this hemisphere, "this would be a very dangerous escalation, a wholly unnecessary one," he said.

Discussing prospects for an arms control agreement, Isakov said, "There is no reason to be optimistic. But, as I have said already, if we are met at least halfway by the United States negotiating team, then there is reason to hope that we can find solutions in this area, because the solution is possible."

Perle said President Reagan has shown great flexibility with his interim proposal, under which the United States will consider reducing nuclear weapons in Europe to any level the Soviets might chose.

On an unrelated subject, Perle said there was nothing improper about his relationship with an Israeli weapons company that paid him a $50,000 consulting fee the month he entered government service.

"In simple fact, I terminated all relationships with all of my business clients when I entered the government as a consultant, and this was some months before I became assistant secretary of defense," he said.

Before joining the Defense Department on March 23, 1981, Perle worked for the Abington Corp., a consulting firm that was owned by John F. Lehman, who is now secretary of the Navy. Israeli arms dealers Shlomo and Chaim Zabludowicz became clients of Perle in 1980.

The New York Times said Perle recommended that the Army consider buying weapons from the Israeli company in 1982, a year after it paid him a $50,000 consulting fee.