The United States could be prepared to -begin talks with the Soviet Union on reducing strategic nuclear weapons as early as June or July, State Department officials say.
Some officials are urging that the talks be opened that soon, partly in order to offset the growing antinuclear movement in Western Europe and in the United States. But a continuing problem is the situation in Poland, which already has helped to slow the timing of such talks.
One official says that there would be considerable political advantage in it for President Reagan if he could announce during his June trip to Europe that the US is ready to begin strategic arms reduction talks. The official says, however, that regardless of what the President says or does during his European trip, he can expect to face sizable protest demonstrations against his defense policies.
Pressure is building in the US Congress, as well as within the bureaucracy, for early talks with the Soviets on nuclear weapons.
In an appearance on the ABC television program ''This Week With David Brinkley'' on April 4, Sen. Henry Jackson (D) of -Washington, who is considered a hawk on defense, said, ''I want to emphasize the need to get on with early talks.''
Senator Jackson, a member of the Senate Armed Services Committee, disagreed with President Reagan's assertion made during a press conference on March 31 that the Soviets held a ''margin of superiority'' over the US in nuclear weaponry. The senator said that despite some imbalances, a ''qualitative advantage'' held by the US in bombers and submarines had to be taken into account.
A number of experts within the government itself are startled by President Reagan's news conference statement on the nuclear balance. Although they are inhibited from saying so publicly, they tend to agree with Jackson that the President's assertion went too far. They consider it potentially damaging to the European allies' confidence in the United States to speak of Soviet superiority.
One official asserts that the Soviets are incapable of tracking US submarines and that this would become even more difficult for the Soviets once the new Trident submarines are deployed. American submarines are said to be much quieter than their Soviet counterparts. The official says that US B-52 bombers are still far superior to anything possessed by the Soviets. And, the official says, once the US deploys its new D-5 missile warhead, it could prove to be extremely threatening to the Soviets' land-based missiles.
The administration is currently narrowing down its negotiating options. But the official says that its final strategic arms negotiating position is likely to include not only limits on nuclear missile launchers, as did the SALT II treaty, but also limits on the size and numbers of warheads.
On the Soviet side, meanwhile, a problem could emerge from the leadership struggle reported to be under way. With President Leonid Brezhnev ailing and possibly on his way out of power, the Soviet leadership may temporarily lack the unity needed to go to the negotiating table.